How to express a number in scientific notation
Write the number in decimal form. Only a digit other than 0 must be before the period, that is, it must be a real number between 1 and 10 (example: 1.5).
Count how many decimal places the point has moved.
Put this number of places as an exponent of 10. You must be careful when walking with the point: if the number decreases, the exponent will be positive (example: 10^5). If the number increases, the exponent will be negative (example: 10^-6).
In this case:
You have the number 2385.9. The point will move 3 decimals to the left. The number will decrease, so the exponent will be positive and the value of it is 3.
So it will be: 2.3859 × 10^3
Answer: 2.3859 × 10^3
Calculate the concentration in mol/L, M, of an aqueous sugar solution with a concUsing the above equation, how many grams of salt ( CaCl2 ) would need to be added to 1 L of water in order for the boiling point of the solution to reach 106 °C ? Assume that the density of water is 1.0 g/mL and that CaCl2 completely dissociates into three ions — i.e., a Ca2+ ion and two Cl− ions. The boiling point constant, kb , for water is 0.515°C/m .entration of 17.0% (w/w) and density of 1.015 g/mL at 25°C . The molecular weight of sugar is 342.30 g/mol. Report your answer to three significant figures.
The molar mass of the sugar is obtained as 1.43 g/mol.
What is the molecular mass?We know that the boiling point of a substance is one of the properties of the substances that could be called the colligative properties since they can be affected by the number of particles present.
We are told that the mass concentration of the substances w/w of the solution is 17% thus we have 17 g of the compound and 83 g of water. We can now get the number of moles of the substance as;
Number of moles = ?
Mass of the solution = 1000 mL * 1.015 g/mL = 1015 g or 1.015 Kg
Given that;
ΔT = K m i
ΔT = Boiling point elevation
K = Boing constant of water
m = molality of the solution
i = Van't Hoff factor
ΔT = 106 °C - 100°C
= 6 °C
Then;
6 = 0.515 * 17/MM * 1/1.015 * 1
Where MM = molar mass of the sugar
6 = 0.515 * 17/1.015 MM * 1
6 = 0.515 * 17/1.015 MM
6 = 8.755/1.015 MM
6 * 1.015 MM = 8.755
MM = 8.755/6 * 1.015
MM = 1.43 g/mol
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chuyển hoá Nh3 - chu trình ure
Answer:
umm translate
Explanation:
What is the frequency of a photon with a wavelength of 159 nm. Report your answers to three significant digits. The frequency is = _________ s-1
Answer
\(Frequency=1.887*10^15s-1\)
Explanation:
Frequency reffers to the number of occurrences of a repeating event per unit of time. It is measured in units of hertz (Hz), it can also be measured as occurrence of a repeating event per second as well
c is the speed of light having value 3*10^8m/s
Given, Wavelength = 159 nm
But n= 10^-9m
Wavelength=159*10^-9
C=frequency* wavelength
Frequency=c/wavelength
Frequency= 3*10^8/159*10^-9
\(Frequency=1.887*10^15s-1\)
Answer:1.89x10^15s₋1
Explanation:
the relationship between frequency and wavelength is given as
c= frequency x wavelength
where c = speed of light - 3.8 x 10 ^8 m/s
given here that wavelength = 159 nm
changing to m becomes 1m= 10⁻9nm,
159nm becomes 159 x10-9m
therefore our frequency will now be
frequency = speed of light (c)/ wavelength
= 3.8x1`0^8/159x10^-9 =1.886 x10^15s⁻1 = 1.89 x10^15s⁻1
How many molecules of CO2 are there in 3.55 g of CO2?
Answer:
4.9∗1022 molecules of CO2 in a 3.6 gram sample.
Explanation:
The gram molecular weight of co2 is 44 gms.
So the number of molecules in 44 gms of co2 is 6.023×10^23 .
Then the number of molecules in 3.6 gms of co2 is (6.023×10^23×3.6)÷44 = 4.92×10^22
75.0 moles of Copper metal reacts with 70.0 moles of chlorine gas to produce copper (II) chloride.
Which reactant is the excess reactant?
Answer:
copper
Explanation:
First, write down the reaction and notice the ratio of moles of which the reactants react.
the equation (i'm too lazy to write states of matter and since it doesnt matter in this problem i'm not going to. it is balanced, however) is:
Cl2 + Cu -> CuCl2
as you can see, one mole of chlorine gas reacts with one mole of copper.
since we have 75 moles of copper but only 70 moles of chlorine gas, after everything has been reacted we would expect 5 moles of copper to be left over. so, copper is the the reactant which is in excess
Name the following compound: CH3CH2CH3
The following compound: CH3CH2CH3 is propane and this a hydrocarbon and is alkane. Propane seems as a drab fueloline with a faint petroleum-like odor.
The vapors are heavier than air and a flame can flash returned to the supply of leak very easily. The leak can be both a liquid or vapor leak. The vapors can asphyxiate through the displacement of air. Under extended publicity to hearthplace or warmness the boxes might also additionally rupture violently and rocket.
CH3 CH2 CH3 is a compound referred to as a hydrocarbon, greater in particular an alkane. The not unusualplace call for this compound is propane, that is a form of fueloline extensively used as a gasoline supply. It is a hydrocarbon as it includes best hydrogen and carbon atoms.
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Write the chemical reactions for the formation of the respective Grignard reagents from the reaction of magnesium with the following organic halides: iodomethane, bromobenzene, chlorocyclohexane
Answer:
Here are the chemical reactions for the formation of the respective Grignard reagents from the reaction of magnesium with the following organic halides:
Iodomethane:Mg + CH3I → CH3MgI
Bromobenzene:Mg + C6H5Br → C6H5MgBr
Chloropropane:Mg + C3H7Cl → C3H7MgCl
Grignard reagents are formed when magnesium metal is reacted with an alkyl halide. The magnesium metal reacts with the halide to form a magnesium halide salt, and the alkyl group is displaced from the halide to form the Grignard reagent.
The Grignard reagent is a powerful nucleophile and can be used to synthesize a variety of organic compounds.
A chemical formula includes the symbols of the elements in the
compound and the subscripts that indicate*
how many atoms or ions of each type are combined in the simplest unit
the formula mass
the number of moles in each element
the charges of the elements or ions
Answer:
it indicates, how many atoms or ions of each type are combined in the simplest unit.
Calculate the numerical value of Kc for
the following reaction if the equilibrium
mixture contains 0.0450 M PCI 3, 0.116
M Cl₂, and 25.8 M PCI 5.
PC 3 (g) + Cl₂ (g) ⇒ PCI5 (g)
(the 5 in PCl is a subscript)
The numerical value of Kc for the given reaction, with the equilibrium mixture containing 0.0450 M PCl3, 0.116 M Cl2, and 25.8 M PCl5, is approximately 4942.03.
To calculate the numerical value of Kc for the given reaction, we need to set up an expression for the equilibrium constant using the concentrations of the species involved.
The balanced equation for the reaction is:
PCl3 (g) + Cl2 (g) ⇌ PCl5 (g)
The equilibrium constant expression, Kc, is given by:
Kc = [PCI5] / ([PCl3] * [Cl2])
Given the equilibrium concentrations:
[PCl3] = 0.0450 M
[Cl2] = 0.116 M
[PCI5] = 25.8 M
Substituting these values into the equilibrium constant expression, we have:
Kc = (25.8 M) / ((0.0450 M) * (0.116 M))
Calculating Kc:
Kc = 25.8 M / (0.00522 M^2)
Kc = 4942.03
Therefore, the numerical value of Kc for the given reaction, with the equilibrium mixture containing 0.0450 M PCl3, 0.116 M Cl2, and 25.8 M PCl5, is approximately 4942.03.
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Why is molecular polarity important for life?
Molecular polarity is important for life because it plays a crucial role in many biological processes.
What is molecular polarity?Molecular polarity refers to the distribution of electrical charge within a molecule. It is a property that results from differences in the electronegativity of the atoms in a molecule.
Molecular polarity is important for life because many biological molecules, including proteins, DNA, and carbohydrates, are polar, meaning they have regions of positive and negative charge.
This allows them to interact with other polar molecules, such as water, through hydrogen bonding, which helps to stabilize their structures and maintain their functionalities.
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13. Salt and benzoic acid in an aqueous solution can be separated with ice and filter paper.
True
False
please help.
question a & b shown in the picture.
1) From the collision theory, the more the concentration of the acid, the more the acid molecules collide with the calcium carbonate causing the rate of reaction to increase.
2) If the student does grind up the calcium carbonate, the rate of reaction would increase.
What is the rate of reaction?We know that the rate of the reaction must have to do how quickly or slowly that reactants can be converted into products or how the products are appearing and then the reactants are disappearing.
Having said this, the keys that we need to answer the question that has been asked to us can be found in the graph that has been attached to the question. It is clear that the rate of the reaction which is the slope of the graph is increasing as the concentration of the acid is seen to increase according to the graph above.
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A lab requires 3.50L of a 2.0M solution of HCl. What volume of a 6.0M solution is needed to make this solution?
Answer:
THE ANSWER IS 1.167L
Explanation:
Which type of macromolecule is the sugar fructose? It ends in "ose" which is a clue.
O lipid
O nucleic acid
O carbohydrate
protein
Answer:
C) Carbohydrate
Explanation:
Sugar is a carbohydate
Carbohydrate is a type of macromolecule is the sugar fructose.
What is carbohydrate?A carbohydrate is a biomolecule consisting of carbon, hydrogen and oxygen atoms. Carbohydrates, or carbs, are sugar molecules which is a main nutrient found in foods and drinks.
Your body breaks down carbohydrates into glucose that provides energy to the body so we can conclude that carbohydrate is type of macromolecule is the sugar fructose.
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6. (1 pt) refer to the synthetic sequences below. in the step with thionyl chloride explain if hexamethylphosphoric triamide (hmpt) or 1,4-dioxane was added along with thionyl chloride. provide a specific rationale.
Hexamethylphosphorous triamide is useful as a reagent in organic synthesis as a phosphorylating agent. It is engaged with carbon tetrachloride for the substitution of hydroxy groups with chlorides.
It is jumbled in the preparation of epoxides and arene oxides from aldehydes and aryldialdehdyes respectively. It is used in the composing of carbonates as well as the reduction of ozonides.
Air and moisture sensitive. Keep the container tightly direct in a dry and well-ventilated place. clashing with strong oxidizing agents.
lower aromatic aldehydes to symmetrical epoxides in good yield. Both cis- and trans-isomers are formed.
Under suitable conditions, the reaction of the intermediate with a second aldehyde can lead to mixed deoxybenzoins or diaryl enamines.
Has also been used for a variation of other reductions including that of ozonolysis intermediates: Helv. Chim. Acta, 50, 2387 (1967), and of primary alkyl nitro compounds to nitriles: Synthesis, 36 (1979).
Bromohydrins can be change to alkenes, by reductive elimination from their triflate esters
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Which of the following statements is true about the strength of the intermolecular forces in CH4 and NH3?
a.CH4 ≥ NH3 because CH4 is tetrahedral but NH3 is pyramidal.
b.CH4 < NH3 because δ− on C in the CH bond is greater than δ− on N in the NH bond.
c.CH4 < NH3 because the NH bond is more polar than the CH bond.
d.CH4 ≥ NH3 because CH4 has H bonding but NH3 has dispersion forces.
Answer:
c.CH4 < NH3 because the NH bond is more polar than the CH bond.
Explanation:
. A potassium dichromate solution was standardized
with the following results: 0.1017, 0.1019, 0.1016,
0.1015 N.
(a) Within what range are you 95% confident that the
true value falls?
(b) Determine if there is a statistical difference between
the obtained mean concentration and the prepared
concentration of 0.1012 N
A) Calculate the lower and upper bounds of the 95% confidence interval:
Lower bound = X - ME
Upper bound = X + ME
B) you would compare the obtained mean concentration (0.101675 N) with the prepared concentration (0.1012 N) and calculate the t-value. The t-value is then compared to the critical t-value at a certain significance level (e.g., a = 0.05) and the degrees of freedom (n-1) to determine if there is a statistically significant difference.
(a) To determine the range within which you can be 95% confident that the true value falls, you can calculate the confidence interval using the obtained results.
First, calculate the mean (X) of the measured concentrations:
X = (0.1017 + 0.1019 + 0.1016 + 0.1015) / 4 = 0.101675 N
Next, calculate the standard deviation (s) of the measured concentrations:
s = sqrt(((0.1017 - X)² + (0.1019 - X)² + (0.1016 - X)² + (0.1015 - X)²) / (4 - 1))
Then, calculate the standard error of the mean (SE) using the formula:
SE = s / sqrt(n)
where n is the number of measurements (in this case, n = 4).
With the standard error, you can calculate the margin of error (ME) for a 95% confidence interval using the t-distribution. The t-value for a 95% confidence interval with 3 degrees of freedom is approximately 3.182.
ME = t * SE
Finally, calculate the lower and upper bounds of the 95% confidence interval:
Lower bound = X - ME
Upper bound = X + ME
(b) To determine if there is a statistical difference between the obtained mean concentration (0.101675 N) and the prepared concentration (0.1012 N), you can perform a t-test. The t-test compares the means of two sets of data to determine if they are significantly different from each other.
Using the formula for a two-sample t-test, you would compare the obtained mean concentration (0.101675 N) with the prepared concentration (0.1012 N) and calculate the t-value. The t-value is then compared to the critical t-value at a certain significance level (e.g., α = 0.05) and the degrees of freedom (n-1) to determine if there is a statistically significant difference.
If the calculated t-value is greater than the critical t-value, it suggests a statistically significant difference between the obtained mean concentration and the prepared concentration.
Please note that the actual calculations and interpretation may vary depending on the statistical software or method used, and it's always recommended to consult a statistician or refer to appropriate statistical references for accurate analysis.
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Ca(NO3)2
Ca(NO2)2
Ca3N2
Correct names
Answer:
Ca(NO3)2 is Calcium Nitrate
Ca(NO2)2 is Calcium Nitrite
Ca3N2 is Calcium Nitride
Explanation:
Answer:
Ca(NO3)2 = Calcium nitrate
Ca(NO2)2 = Clacium nitrite
Ca3N2 = Calcium nitride
Which portion of a molecule of F2O has partial positive charge?
Question 3 options:
A)
The F atoms
B)
The central O atom
C)
The partial charge on each atom is zero
D)
The partial charge on each atom is negative
The partial charges on each fluorine atom are negative. Option B) The central O atom is the correct answer. Option B
The partial charges in a molecule are determined by the electronegativity values of the atoms involved. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. In the case of \(F_2O\), fluorine (F) is more electronegative than oxygen.
Fluorine is the most electronegative element on the periodic table, meaning it has a high ability to attract electrons. Oxygen is also relatively electronegative but less so than fluorine. When fluorine atoms bond with oxygen, the shared electrons will be pulled more towards the fluorine atoms, creating a polar covalent bond.
In \(F_2O\), each fluorine atom will pull the shared electrons towards itself, resulting in a higher electron density around the fluorine atoms. This creates a region of partial negative charge around the fluorine atoms.
Conversely, the oxygen atom will have a region of lower electron density and, therefore, a partial positive charge. This is because the shared electrons spend more time around the fluorine atoms due to their higher electronegativity.
Option B
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If an object has a density of 6.05 g/cm3 and a volume of 36.5 cm3, what is its mass?
Answer:
0.42 g/cm3
Explanation:
Answer:
20/40=0.5 g/cm^3 becuase, mass/volume=density
Explanation:
use dimensional analysis to solve all of the following:
0.5 moles of \(H_{2\)\(O_{2}\) produces 8 grams of \(O_{2}\).
What is Moles?
Mole is a unit of measurement used in chemistry to express the amount of a substance. It is defined as the amount of a substance that contains the same number of entities (such as atoms, molecules, or ions) as there are atoms in 12 grams of carbon-12. This number is known as Avogadro's number.
To use dimensional analysis, we need to set up the given equation in terms of units. We can use the molar mass of\(H_{2}\)\(O_{2}\) and \(O_{2}\) to convert between moles and grams:
2\(H_{2}\)O2 → 2\(H_{2}\) + \(O_{2}\)
The balanced equation shows that 2 moles of \(H_{2}\)\(O_{2}\) produce 1 mole of \(O_{2}\). We can use this ratio to convert between moles of \(H_{2}\)\(O_{2}\)and moles of\(O_{2}\).
0.5 moles of \(H_{2}\)O2 x (1 mole of \(O_{2}\) / 2 moles of\(H_{2}\)\(O_{2}\)) = 0.25 moles of \(O_{2}\)
Now we can use the molar mass of \(O_{2}\) to convert moles to grams:
0.25 moles of \(O_{2}\) x (32 g of \(O_{2}\) / 1 mole of \(O_{2}\)) = 8 g of \(O_{2}\)
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How does the amount of sunlight affect the number of eggs laid by a chicken?
Explanation:
The amount of daylight hours affects a chicken's reproductive cycle. Hens will begin laying when the amount of daylight reaches 14 hours per day during early spring. Maximum egg laying will occur when the day length reaches 16 hours per day
If 15.00 mL of 0.0100 M Ca(IO3)2 solution are mixed with 0.500 g KI, what is the theoretical yield (in grams) of I2?
The theoretical yield of I2 in the reaction would be 0.23 g
Theoretical yieldThis refers to the stoichiometric yield of a reaction.
From the equation of the reaction:
Ca(IO3)2 + 10 KI + 12 HCl → 6 I2 + CaCl2 + 10 KCl + 6 H2O
The mole ratio of Ca(IO3)2 and I2 is 1: 6
Mole of 15.00 mL, 0.0100 M Ca(IO3)2 = 15/1000 x 0.0100
= 0.00015 mole
Equivalent mole of I2 = 0.00015 x 6
= 0.009 mole
mass of 0.0009 I2 = 0.0009 x 253.809
= 0.23 g
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Which of the following methods of fossil formation is formed in dry areas due to a lack of moisture?
a
Mummification
b
Casts and molds
c
Amber fossil
d
Carbonization
The methods of fossil formation in dry areas due to a lack of moisture is mummification. The correct option is a.
What is mummification?Mummification is the process of deliberately drying or embalming flesh to preserve the body after death.
This typically entailed removing moisture from a deceased body and desiccating the flesh and organs with chemicals or natural preservatives such as resin.
Mummification served the purpose of keeping the body intact so that it could be transported to a spiritual afterlife.
The body was stripped, positioned on a slanted table, and washed in natron solution (a naturally occurring salt used both as soap and a preservative).
The brain was extracted from the skull through a hole in the ethmoid bone (the bone separating the nasal cavity from the skull cavity).
Thus, the correct option is A.
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3.Two molecules of mercury oxide decompose into 2 molecules of mercury and 1 molecule of oxygen gas. Which of the following equations correctly describes this reaction?Select one:a. Ab. Bc. Cd. D
Answer
Explanation
If two molecules of mercury oxide decompose into 2 molecules of mercury and 1 molecule of oxygen gas, then the equation for the reaction is shown below
\(2HgO(s)\rightarrow2Hg(l)+O_2(g)\)What are 3 elements similar to silver
Answer:
Copper, Sodium, and Francium
Explanation:
A 0.982-g sample of an unknown gas exerts a pressure of 700 mm Hg in a 450-cm3 container at 23oC. Calculate the molar mass of this gas. [1cm3 = 1mL; 1000mL = 1L]
Answer:
57.4 g/mol
Explanation:
Step 1: Convert 450 cm³ to L
We will use the conversion factors 1 cm³ = 1 mL and 1000 mL = 1 L.
450 cm³ × 1 mL/1 cm³ × 1 L/1 mL = 0.450 L
Step 2: Convert 23 °C to Kelvin
We will use the following expression.
K = °C + 273.15 = 23 + 273.15 = 296 K
Step 3: Calculate the number of moles of the gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 700 mmHg × 0.450 L / (62.4 mmHg.L/mol.K) × 296 K = 0.0171 mol
Step 4: Calculate the molar mass of the gas
0.982 g of the gas correspond to 0.0171 moles.
M = 0.982 g/0.0171 mol = 57.4 g/mol
need help whoever answers will be awarded branliest answer
Answer:
1.used to seperate solids from liquids, and is a act of pouring a mixture onto a membrane this allows the passage of liquid and results in the collection of a solid
2. the solution would passed through without losing and solids
3 would allow them to dry or on further hearing decompose
Explanation:
Q16. Choose whether this is a physical or chemical change. *
cream
being
whipped
Because air puffs up the cream as it is whipped, there is a physical change even though the ingredients are still cream and air.
What is physical change ?Physical modifications are those that affect a chemical substance's form but not its chemical content. Physical changes may normally be used to separate compounds into chemical elements or simpler compounds, but they cannot be used to separate mixtures into their component compounds.
Liquid cream is extensively combined with small air bubbles to form the foam colloid known as whipped cream. Because milk is transformed from a colloid (cream) to a solid (butter) without changing its chemical makeup, turning milk into butter is a physical transformation. This change in the body can be undone.
Thus, there is a physical change even though the ingredients are still cream and air.
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Give and proidi the following after and undergoing alpha decay and beta decay
The products of the alpha decay of radium-226 and the beta decay of carbon-14 are radon-222 and nitrogen-14, respectively.
The alpha decay of radium-226 results in the emission of an alpha particle, which is a helium nucleus consisting of two protons and two neutrons.
Therefore, the product of the alpha decay of radium-226 is radon-222:
Ra-226 → Rn-222 + alpha particle
On the other hand, In the case of carbon-14, beta minus decay occurs, in which a neutron is converted into a proton, and an electron and an antineutrino are emitted.
So carbon-14 becomes nitrogen-14:
C-14 → N-14 + beta particle
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--The complete Question is, What is the product of the alpha decay of radium-226 and the beta decay of carbon-14?--