Which lists the correct order of the steps? 4,2,1,3 4,1,3,2 4,3,1, 2 4, 2, 3.1

A 30.7 g sample of Strontium nitrate, Sr(NO3)2•nH2O, is heated to a constant mass of 22.9 g. Calculate the hydration number.

Elodia [21]

Answer:

Hydration number: 4

Explanation:

1) Mass of water in the hydrated compound

Mass of water = Mass of the hydrated sample - mass of the dehydrated compound

Mass of water = 30.7 g - 22.9 g = 7.8 g

2) Number of moles of water

Number of moles = mass in grams / molar mass

molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol

Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol

3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂

The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g

Molar mass of Sr (NO₃)₂ : 211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).

Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol = 0.108 mol

4) Ratio

0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈ 4 mol H₂O : 1 mol Sr (NO₃)₂

Which means that the hydration number is 4.

4 0

4 years ago

Read 2 more answers

An ionic bond can be formed when one or more electrons are 1) equally shared by two atoms 2) unequally shared by two atoms 3) tr

Lyrx [107]

Answer:

4) transferred from the valence shell of one atom to the valence shell of another atom

Explanation:

Electrons are located outside of the nucleus which contains the protons and the neutrons.

For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms.

In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds.

6 0

3 years ago

When solving an equation using Gay-Lussac's law, which of the following steps do not apply? A. List your knowns and unknowns. B.

suter [353]

Answer:

C. Plug the unknowns into the ideal gas law formula.

Explanation:

Gay-Lussac's law states that:

"For a constant mass of an ideal gas kept at constant volume, the pressure of the gas is directly proportional to its absolute temperature"

Mathematically, it can be written as:

$\frac{p_1}{T_1}=\frac{p_2}{T_2}$

where

p1 is the initial pressure

T1 is the initial temperature (in Kelvin)

p2 is the final pressure

T2 is the final temperature (in Kelvin)

Therefore, in order to solve for one of the 4 variables, the following steps must be adopted:

A. List your knowns and unknowns.

B. Convert temperature to kelvin.

D. Solve for the unknown.

While the following step is not needed:

C. Plug the unknowns into the ideal gas law formula.

Because we do not need to use the ideal gas law formula.

8 0

3 years ago

Aspartame (c14h18n2o5) is a solid used as an artificial sweetener. its combustion produces carbon dioxide gas, liquid water, and

Law Incorporation [45]

Aspartame (C₁₄H₁₈N₂O₅) is a solid used as an artificial sweetener. its combustion produces carbon dioxide gas, liquid water, and nitrogen gas

C₁₄H₁₈N₂O₅ + 16O₂-----> 14CO₂ + 9H₂O + N₂.

As it can be seen from the equation, that the coefficient of nitrogen gas in the balanced equation for the reaction is 1.

So the answer here is 1 only that is coefficient of nitrogen gas in the balanced equation for the reaction is 1.

5 0

4 years ago

What is meant by Vulcanicity?

scZoUnD [109]

The quality or state of being volcanic.

3 0

3 years ago

Which lists the correct order of the steps? 4,2,1,34,1,3,2 4,3,1, 24, 2, 3.1​

Which lists the correct order of the steps? 4,2,1,34,1,3,2 4,3,1, 24, 2, 3.1