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4 years ago

What kind of thermochemical equation is represented below?

1 answer:

6 0

The kind of thermochemical equation represented below

that is
CaO(s) + H2O (l) = Ca(OH)2 (s) +65.2 kj

is exothermic ( answer B)
This is because its heat energy has a + sign meaning that heat is released by the reaction above.

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Hydrogen gas is collected over water in an inverted buret. If the atmospheric pressure is 745 mm Hg, the vapor pressure of water

Varvara68 [4.7K]

Answer:

$P_{H_2}=727mmHg$

Explanation:

Hello there!

In this case, according to the given data, it is possible to infer that the gas mixture lies on the 15.0 cm-high column of water, so that the total pressure or atmospheric pressure is given by:

$P_{atm}=P_{water}+P_{H_2}$

Thus, since the atmospheric pressure is 745 mmHg and the vapor pressure of water is 18 mmHg, the pressure of hydrogen turns out to be:

$P_{H_2}=P_{atm}-P_{water}\\\\P_{H_2}=745mmHg-18mmHg\\\\P_{H_2}=727mmHg$

Best regards!

6 0

3 years ago

If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of He occupy under

WINSTONCH [101]

Answer:

the volume occupied by 3.0 g of the gas is 16.8 L.

Explanation:

Given;

initial reacting mass of the helium gas, m₁ = 4.0 g

volume occupied by the helium gas, V = 22.4 L

pressure of the gas, P = 1 .0 atm

temperature of the gas, T = 0⁰C = 273 K

atomic mass of helium gas, M = 4.0 g/mol

initial number of moles of the gas is calculated as follows;

$n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1$

The number of moles of the gas when the reacting mass is 3.0 g;

m₂ = 3.0 g

$n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol$

The volume of the gas at 0.75 mol is determined using ideal gas law;

PV = nRT

$PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\ then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L$

Therefore, the volume occupied by 3.0 g of the gas is 16.8 L.

4 0

3 years ago

The number of protons in an atom's nucleus determines its

Nataly [62]

Number of proton present in the nucleus determines the atomic number of an element. It determines <span>chemical properties, which is why all atoms with proton count (atomic number) 6 are carbon</span>

8 0

3 years ago

Read 2 more answers

How many protons does this atom have?:____

Allisa [31]

Answer:

1.6

2.8

3.6

Explanation:

4 0

3 years ago

Read 2 more answers

HELP PLEASE

Tatiana [17]

Answer:

Samira's model correctly demonstrates how the properties changed with the rearrangement of the atoms. However not all atoms are accounted for. There is a missing reactant.

Explanation:

Samira's model correctly demonstrated how the atoms in two compounds reacted to form two new products. However, the elements present in the reactants side should be the elements that make up the new products in the product side. But as the diagram shows, Sameera has mistakenly added a new element to one of her products which will be wrong.

7 0

3 years ago