Certainly! Let's solve this problem step-by-step.
1. Understand the given values:
- The mass of milk, [tex]\( \text{mass} = 4.00 \)[/tex] grams.
- The enthalpy of combustion, [tex]\( \Delta H_{\text{comb}} = -210.7 \)[/tex] Joules per gram.
2. Recall the formula for calculating the heat of combustion ([tex]\( q_{\text{comb}} \)[/tex]):
[tex]\[
q_{\text{comb}} = \text{mass} \times \Delta H_{\text{comb}}
\][/tex]
3. Substitute the given values into the formula:
[tex]\[
q_{\text{comb}} = 4.00 \, \text{grams} \times (-210.7 \, \text{Joules/gram})
\][/tex]
4. Perform the multiplication to find the heat of reaction:
[tex]\[
q_{\text{comb}} = 4.00 \times -210.7 = -842.8 \, \text{Joules}
\][/tex]
So, the heat of reaction, [tex]\( q_{\text{comb}} \)[/tex], is:
[tex]\[
q_{\text{comb}} = -842.8 \, \text{J}
\][/tex]
This value indicates that 842.8 Joules of energy are released during the combustion of 4.00 grams of milk, hence the negative sign.
