Explanation:
1. Thermochemical equation is balance stoichiometric chemical equation written with the phases of the reactants and products in the brackets along with the enthalpy change of the reaction.
The given correct thermochemical reactions are:


2. Phase change affect the value of the enthalpy change of the thermochemical equation. This is because change in phase is accompanied by change in energy. For example:


In both reaction phase of water is changing with change in energy of enthalpy of reaction.
The cubes have only the same volume, so the answer is c.
Answer:
Final temperature = 
Explanation:
Given that,
Heat added, Q = 250 J
Mass, m = 30 g
Initial temperature, T₁ = 22°C
The Specific heat of Cu= 0.387 J/g °C
We know that, heat added due to the change in temperature is given by :

Put all the values,

So, the final temperature is equal to
.
Answer:
synthesis
Explanation:
I believe answer is d a synthesis reaction
Answer:
462g
Explanation:
First, let us calculate the molar mass of Cu(CN)2. This is illustrated below:
Molar Mass of Cu(CN)2 = 63.5 + 2(12+14) = 63.5 + 2(26) = 63.5 + 52 = 115.5g/mol
Number of mole of Cu(CN)2 given from the question = 4moles
Mass = number of mole x molar Mass
Mass of Cu(CN)2 = 4 x 115.5
Mass of Cu(CN)2 = 462g