When does a change in energy occur?

Binary compounds of alkali metals and hydrogen react with water to liberate hydrogen gas. The hydrogen gas from the reaction of

DanielleElmas [232]

Answer: The mass of $H_{2}$ liberated is 0.0383 g and the mass of NaH that reacted 0.455 g.

Explanation:

The given data is as follows.

Volume = 0.501 L,

Temperature of gas = $35^{o}C$ = (35 + 273) K = 308 K,

Total pressure = 760 mm Hg

Vapor pressure of water at $35^{o}C$ = 422 mm Hg

Partial pressure of $H_{2}$ = (760 - 422) mm Hg

= 717.8 mm Hg

The chemical equation is as follows.

$NaH + H_{2}O \rightarrow NaOH + H_{2}$

Using ideal gas equation, we will find the moles of hydrogen gas as follows.

PV = nRT

n = $\frac{PV}{RT}$

As we know,

1 atm = 760 mm Hg

717.8 mm Hg = $717.8 \times \frac{1 atm}{760 mm Hg}$

= 0.944 atm

Putting the given values into the above formula we will calculate the number of moles as follows.

n = $\frac{PV}{RT}$

= $\frac{0.944 atm \times 0.510 L}{0.08206 Latm/mol K \times 308 K}$

= 0.0190 moles

Now, we will find the mass of $H_{2}$ as follows.

Mass = Moles × Molar mass

= 0.0190 moles × 2.01588 g/mol

= 0.0383 g

Therefore, mass of hydrogen is 0.0383 g.

As the ratio between $H_{2}$ and NaH is 1:1. So, we will calculate the moles of NaH as follows.

Mass = Moles × Molar mass

= 0.0190 moles × 23.99771 g/mol

= 0.455 g

Therefore, mass of NaH is 0.455 g.

6 0

3 years ago

What is the difference between ionic formula and the molecular formula?

Kaylis [27]

Answer:

Molecular compounds are pure substances formed when atoms are linked together by sharing of electrons while ionic compounds are formed due to the transfer of electrons. 2. ... Molecular compounds are formed between two non-metals while ionic compounds are formed between metals and non-metals.

3 0

2 years ago

As the sun heats the surface of the ocean, two layers of water result. What separates the layers.

pychu [463]

Question: As the sun heats the surface of the ocean, two layers of water result. What separates the layers.?

Answer: The Thermocline

Hope this helps!.

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~A.W~ZoomZoom44

4 0

3 years ago

A scientist discovered a microscopic unicellular organism with no nucleus which of the following correctly describes the organis

boyakko [2]

The correct option is this: THE ORGANISM IS A PROKARYOTES.
There are basically two types of cells, prokaryotic and eukaryotic cells. The prokaryotic cells are primitive cells which contain only a few materials which are not well organised. This type of cells is usually found in microscopic organisms. The cells lack organised nucleus and cell organelles which have membranes.

7 0

3 years ago

Read 2 more answers

Which macromolecules break apart by hydrolysis?

ankoles [38]

Answer:

Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy. Carbohydrates, proteins, and nucleic acids are built up and broken down via these types of reactions, although the monomers involved are different in each case.

Explanation:

4 0

2 years ago