Answer:
-5.51 kJ/mol
Explanation:
Step 1: Calculate the heat required to heat the water.
We use the following expression.

where,
- c: specific heat capacity
- m: mass
- ΔT: change in the temperature
The average density of water is 1 g/mL, so 75.0 mL ≅ 75.0 g.

Step 2: Calculate the heat released by the methane
According to the law of conservation of energy, the sum of the heat released by the combustion of methane (Qc) and the heat absorbed by the water (Qw) is zero
Qc + Qw = 0
Qc = -Qw = -22.0 kJ
Step 3: Calculate the molar heat of combustion of methane.
The molar mass of methane is 16.04 g/mol. We use this data to find the molar heat of combustion of methane, considering that 22.0 kJ are released by the combustion of 64.00 g of methane.

Answer:
The pressures will remain at the same value.
Explanation:
A catalyst is a substance that alter the rate of a chemical reaction. It either speeds up the or slows down the rate of a chemical reaction.
While a catalyst affects the rate, it is noteworthy that it has no effect on the equilibrium position of the chemical reaction. A catalyst works by creating an alternative pathway for the reaction to proceed. Most times, it decreases the activation energy needed to kickstart the chemical reaction.
Hence, we know that it has no effect on the equilibrium position. Factors affecting equilibrium position includes, temperature and concentration of reactants and products( pressure in terms of gases).
The reactants and the products here are gaseous, and as such pressure affects the equilibrium position. Now, we have established that the equilibrium position is unaffected. And as such the pressure affecting it does not change.
Thus, we have established that the pressure of the products and reactants are unaffected and as such they remain at their value unaffected.
Answer:
<h2>136.2 mL</h2>
Explanation:
The volume of a substance when given the density and mass can be found by using the formula

From the question
mass = 425
density = 3.12 g/cm³
We have

Since cm³ = mL
We have the final answer as
<h3>136.2 mL</h3>
Hope this helps you
<span>79.70 grams
First, calculate the molar mass of Na2CO3 by looking up the molar mass of the elements used in it.
Sodium = 22.989769
Carbon = 12.0107
Oxygen = 15.999
Multiply each molar mass by the number of atoms used, and sum the results to get the molar mass
2 * 22.989769 + 12.0107 + 3 * 15.999 =105.9872
Finally, multiply the molar mass by the number of moles you need.
0.752 * 105.9872 = 79.7024 grams</span>