Answer : The initial temperature of system 2 is, 
Explanation :
In this problem we assumed that the total energy of the combined systems remains constant.
The mass remains same.
where,
= heat capacity of system 1 = 19.9 J/mole.K
= heat capacity of system 2 = 28.2 J/mole.K
= final temperature of system =
= initial temperature of system 1 =
= initial temperature of system 2 = ?
Now put all the given values in the above formula, we get
Therefore, the initial temperature of system 2 is, 
Answer: option (1) decreases.
Explanation:
May be you have experienced that: when you go to the beach, where the atmposhpere pressure is greater than the atmosphere pressure in places that are at higher altitudes, the water takes longer to boil. That is because the boiling temperature is greater, and you need more total heat (more time) to permit the liquid to reach that temperature.
The reason why that happens is because substances boil when the vapor pressure (the pressure of the particles of vapor over the liquid) equals the atmosphere pressure. So, when the atmposhere pressure increases, the temperature at which the vapor pressure reaches the atmosphere pressure also increases, and when the atmosphere pressure decreases, the temperature at which the vapor pressure reaches the atmosphere pressure decreases.
I’m so sorry if it’s wrong but I think it’s this.....
Answer:
2NaHCO3(s) = Na2CO3(s) + CO2(g) + H2O(g).
And I found it on Quora.com
By the way NaHCO3 is Sodium bicarbonate but a.k.a Baking soda
Hoped this helped :)