Perform the calculation and report the answer using the proper number of significant figures.

Question

Perform the calculation and report the answer using the proper number of significant figures. Make sure the answer is rounded correctly.

1.012×10−3 J/(0.017456 g)(298.3682−298.3567)K=?



Answer 1

It appears that the parentheses in this problem are not done correctly. The problem (based on the units being used) is the calculation of specific heat capacity which uses the equation:

If this is truly the equation being used, then the problem should read:

(1.012×10⁻³ J)/[(0.017456 g)(298.3682−298.3567)K] = ?

This means that 1.012x10^-3 is being divided by both 0.017456 g and by (298.3682 − 298.3567)K

I'll do the problem like that:

First 1.012×10⁻³ J has 4 sig figs, 0.017456 g has 5 sig figs, and both 298.3682K and 298.3567K have 7 sig figs. The final answer will have 4 sig figs (lowest of these)

(1.012×10⁻³ J)/[(0.017456 g)(298.3682−298.3567)K] = 5.041246563 and rounding to 4 sig figs gives 5.041. The units are J/(gK)

5.041 J/(gK)