The energy can be shown as:
Q = ms dT
Whereas, m is the mass of block
s is specific heat
dT is change in temperature.
Copper block having the lowest specific heat and thus having the higher change in temperature and therefore having the higher final temperature.
Answer:
In the option(A) moles of HCl left are 0.100 moles which is wrong, making the option incorrect.
Explanation:

Moles of HCl = n
Molarity of HCl = 1.0M
Volume of HCl solution = 30.0 mL = 0.030 L (1 mL = 0.001L)


Moles of Fe = 
According to recation , 1mol of Fe reacts with 2 mol HCl. Then 0.01 mole of Fe will recat with :
of HCl
This means that HCl uis in excess , hence excessive reagent.
Moles of HCl left unreacted :
= 0.030 mol - 0.020 mol = 0.010 mol
But in the option moles of HCl left are 0.100 moles which is wrong, making the option incorrect.
Answer:
This question appear incomplete
Explanation:
This question appear incomplete. However, fuel is formed through a natural phenomenon involving the conversion of large amount dead and decayed organisms (usually algae and zooplanktons) to combustible fuel through exposure to relatively high temperature and pressure (over millions of years) in the earth's crust. Thus, since this involves a sort of absorption of heat energy (from the earth's crust), it can be referred to be an endothermic reaction.