I need help with this question. Instruction : Answer the following questions using the given options.

Questions :
1. The reaction between an acid and a base is an example of ___ reaction ?

a. Valence
b. Endothermic reaction
c. Chemical reaction
d. Exothermic reaction

2.The following are the factors affecting the rate of a chemical reaction except ___
a. catalyst
b. nature of reactants
c. activation energy
d. lights

3.___ gives a dense white fume when in contact with HCL
a. propane
b. ammonia
c. tetraoxosulphate(vi) acid d. water​

answer; capital earns interest; entrepreneurship receives a profit or incurs a loss;

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol