In the presence of excess oxygen, methane gas burns in a constant-pressure system Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. to yield carbon dioxide and water: CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) ΔH = -890.0 kJ Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

The value of q for the given reaction is -105.9 kJ

Explanation:

To calculate the number of moles, we use the equation:

Given mass of methane = 1.90 g

Molar mass of methane = 16 g/mol

Putting values in above equation, we get:

For the given chemical equation:

To calculate the enthalpy change of the reaction, we use the equation:

where,

q = amount of heat released = ?

n = number of moles = 0.119 moles

= enthalpy change of the reaction = -890.0 kJ/mol

Putting values in above equation, we get:

Hence, the value of q for the given reaction is -105.9 kJ

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

can you list the answers so i can answer