Answer: 2.744 x 1025 molecules
The conservation of mass states that the total mass of reactants present before the reaction occurs is equal to the total mass of products after the reaction. From the choices, the second choice deems fit for the description of the law.
Answer:
The answer is "17200 years".
Explanation:
Given:
Let the half-life of carbon-14, is beta emitter, is 
Constant decay 
The artifact age 
<span>This question asksyou to apply Hess's law.
You have to look for how to add up all the reaction so that you get the net equation as the combustion for benzene. The net reaction should look something like C6H6(l)+ O2 (g)-->CO2(g) +H2O(l). So, you need to add up the reaction in a way so that you can cancel H2 and C.
multiply 2 H2(g) + O2 (g) --> 2H2O(l) delta H= -572 kJ by 3
multiply C(s) + O2(g) --> CO2(g) delta H= -394 kJ by 12
multiply 6C(s) + 3 H2(g) --> C6H6(l) delta H= +49 kJ by 2 after reversing the equation.
Then,
6 H2(g) + 3O2 (g) --> 6H2O(l) delta H= -1716 kJ
12C(s) + 12O2(g) --> 12CO2(g) delta H= -4728 kJ
2C6H6(l) --> 12 C(s) + 6 H2(g) delta H= - 98 kJ
______________________________________...
2C6H6(l) + 16O2 (g)-->12CO2(g) + 6H2O(l) delta H= - 6542 kJ
I hope this helps and my answer is right.</span>
2)NCl3
4)N2O3
5)NH3
6)B2H2
7)K3P
8)OF2
9)Mg(NO3)2
10)Al2(CO3)3
