The answer is force.
Hope this helps.
<h3><u>Answer;</u></h3>
Molarity = 0.25 M
<h3><u>Explanation;</u></h3>
Molarity is given by moles/Liter.
First we find moles:
Number of moles = Mass /molar mass
= (10.7g NH4Cl)/(53.5g/mol NH4Cl)
= 0.200 moles NH4Cl
Then we convert to liters:
= (800mL)*(1L/1000mL) = 0.800L
Therefore; molarity = 0.2moles/0.8L
= 0.25M
Heat needed=mcθ
=7×0.031×(42-17)
=5.425cal
