Please help this is my chemistry work

3. Ethanol has a density of 0.800 g/mL. a. What is the mass of 225 mL of ethanol?

dedylja [7]

Since the ethanol has a density of 0.800 g/mL, the mass of the ethanol is 180 grams.

Given the following data:

Volume of ethanol = 225 mL

Density of lead ball = 0.800 g/mL.

To find the mass of the ethanol;

Density can be defined as mass all over the volume of an object.

Mathematically, the density of a substance is given by the formula;

$Density = \frac{Mass}{Volume}$

Making mass the subject of formula, we have;

$Mass = Density \times Volume$

Substituting the given parameters into the formula, we have;

Mass of ethanol = 180 grams.

3 0

3 years ago

What is the molarity of the Ca(OH)2 solution if 32.00 mL of Ca(OH)2 requires 16.08 mL of a 2.303 M solution for complete titrati

amm1812

Answer:

For this problem we just need to remember the equation and that the volume is always in liters: MaVa=MbVb

Ma= 1.338 mol/L Va= 18.75 mL= 0.01875 L Mb= x Vb=24.73 mL= 0.02473 L

So now we can plug into the equation and solve:

1.338 mol/L * 0.01875 L= x mol/L * 0.02473 L

This is a two step process: stoichiometry and using the answer from the first part to plug and chug it into the Molariy equation.

First step: setup the stoichiometry problem:

3.1171 g Na2CO3 * (1 mol/106 g) * (2 mol HCl/ 1 mol Na2CO3)= mol HCl

Second step: Molarity equation

Molarity= moles HCl/ L M= mol HCl/0.04027 L

For the third problem, you will just use the same equation as the first: MaVa= MbVb

Ma=0.57 M Va= x L Mb= 0.875 M Vb= 23.83 mL= 0.02383 L

0.57 M * x L= 0.875 M * 0.02383 L

With this equation, we want to find the moles of NaOH by using the molarity equation first then because MaVa= MbVb, we know that the number of moles has to be equal.

0.75 M= x mol/ 0.0227 L mol NaOH = 0.75 M *0.0227 L mol NaOH= 0.017025

So next, we can set it to the mass of the acid using this equation: Molar Mass= mass/ moles

Molar Mass= 3.6 g/ 0.017025 mol

And with that you will find the molar mass of HX, and even determine what X is.

Explanation:

hope I helped

8 0

3 years ago

Which of the following has the largest molecular weight? Question 2 options: NO2 N2O CO2 H2S

Marizza181 [45]

Answer:

NO2

I got it right

6 0

2 years ago

Which of the statements regarding alcohols and ethers are true? 1-Propanol is more likely to be a liquid at 50 °C50 °C than is m

irina [24]

Answer:

Following statements are true:

1-Propanol is more likely to be a liquid at 50 than is methoxyethane (ethyl methyl ether).

Alcohol molecules can form hydrogen bonds among themselves;ether molecules cannot

Explanation:

1-Propanol is more likely to be a liquid at 50 than is methoxyethane (ethyl methyl ether).

This is true

Propanol has a boiling temperature (this is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor) of 97-98 °C while methoxyethane a boiling point of 7.4 °C.

This means at 50 °C propanol is liquid but methoxyethane at 50°C is a gas.

Methoxyethane (ethyl methyl ether) is more soluble in water than is 1-propanol.

This false:

Propanol has a hydrogen bonding. The OH on the alcohol can form a hydrogen bond (as a hydrogen acceptor and donor). Water can hydrogen bond. This means alcohol is will disolve in water. ( Remember Like dissolves like). So, when you have a molecule that can act as a donor and acceptor you end up with a much better interaction with water and end up with something that is more miscible. Ethers are only acceptors since they do not have a hydrogen attached to the oxygen. So, they can only accept a proton from water.

Methoxyethane (ethyl methyl ether) is more likely to be a liquid at 50 °C50 °C than is 1-propanol

This is false because propanol has a boiling temperature (this is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor) of 97-98 °C while methoxyethane a boiling point of 7.4 °C.

This means at 50 °C propanol is liquid but methoxyethane at 50°C is a gas.

Alcohol molecules can form hydrogen bonds among themselves;ether molecules cannot

This is true because:

Ether molecules cannot form hydrogen bonding between themselves because the oxygen atom is attached to 2 alkyl or aryl groups R-O-R, e.g diethyl ether, or Ar-O-Ar, such as diphenylether (C6H5)2O

C2H5-O-C2H5,m or dimethyl ether CH3—O-CH3. however they can between ether molecules and other molecules containing hydrogen atoms, such as alcohols, CH3OH. Any molecule with the hydrogen attached to a strongly electronegative element e.g Nitrogen or fluorine.

Methoxyethane (ethyl methyl ether) has a higher boiling point than 1-propanol.

This is false: Methoxyethane has a boiling point of 7.4 °C while propanol has a boiling point of 97-98 °C. This can be shown because at roomtemperature Methoxyethane is a gas but propanol is a liquid.

6 0

3 years ago

1. Nuclear decay by alpha particle emission is more common in atoms of elements that:

11111nata11111 [884]

Answer 1) Option a) have an atomic number greater than 83

Explanation : Nuclear decay by alpha particle emission is more common in atoms of elements that have an atomic number greater than 83. Nuclear reactions occurs with the elements which have mass number more than 200.

Answer 2) Option D) $He^{4}_{2}$

Explanation : In the given nuclear reaction of helium;

$He^{3}_{2} + He^{3}_{2} ----->$ $He^{4}_{2} + 2 P^{1}_{1}$

Two helium isotopes combines to give another helium isotope with emission of a proton (P).

Answer 3) Option D) The products are more radioactive than the reactants.

Explanation : The major drawback of a nuclear fission reaction to be used as an reliable energy source is that it usually produces the products which are found to be more radioactive than the reactants.

Answer 4) Option D) All of the above concerns.

Explanation : Nuclear reactions are usually very harmful in nature. It raises many concerns about the waste disposal that is generated from the reaction. It also requires safe operation for the working nuclear plants. It can also be misused for nuclear weapon proliferation. Hence, the answer is all of the above.

Answer 5) False.

Explanation : The energy output of the Sun and other stars is a result of fusion reactions among hydrogen nuclei. In fusion reactions usually additions takes place.

Answer 6) Option B) The "missing" mass has been converted to energy

Explanation : The total mass of a helium nucleus not equal to the mass of its individual parts because the missing mass has to be converted into energy.

Answer 7) Option A) less than the mass-energy of the products

Explanation : In a nuclear reaction, the mass-energy of the reactants is generally less than that of the mass-energy of the products because some energy has to be generated while the reaction is progressing.

Answer 8) Option D) $9.00 X 10^{17} J$