Answer:
Q = 3937.56 J
Explanation:
Heat transferred due to change in temperature is given by :

c is the specific heat of water, c=4.18 J/g-°C
We have, m = 15 g, 
So,

Hence, 3937.56 J of heat is transferred.
Those elements with similar properties are in the same column.
Answer:
MgCl₂+ Na₂CO₃ ==> MgCO₃ + NaCl
From a quick observation
You see that the right hand side of the eqn is deficient of Sodium and Chlorine
Simply Add a Coefficient of 2 to NaCl to balance it with the left.
Your answer now becomes
MgCl₂ + Na₂CO₃ ==> MgCO₃ + 2NaCl.✅
To get the ∆S of the reaction, we simply have to add the ∆S of the reactants and the ∆S of the products. Then, we get the difference between the ∆S of the products and the ∆S of the products. If the <span>∆S is negative, then the reaction spontaneous. If the otherwise, the reaction is not spontaneous.</span>