Home > Chemistry > Energy Change in Reactions

If 100.00 J are added to 20.0 g water at 30.0°C, what will be the final temperature of the water?

Answer 1

Olivia Anton

The final temperature of the water will be 31.2 °C.

The equation for a substance's heat gain or loss is

#color(blue)(bar(ul(|color(white)(a/a)q = mcΔTcolor(white)(a/a)|)))" "#

This equation can be rearranged to get

#ΔT = q/(mc)#

In this issue,

#q = "100.00 J"# #m = "20.0 g"# #c = "4.178 J·K"^"-1""g"^"-1"#

#ΔT = (100.00 color(red)(cancel(color(black)("J"))))/(20.0 color(red)(cancel(color(black)("g"))) × "4.178 J"·color(red)(cancel(color(black)("K"^"-1""g"^"-1")))) = "1.197 °C"#

#ΔT = T_"f" - T_"i" = T_"f"color(white)(l) "- 30.0 °C" = "1.197 °C"#

#T_"f" = "30.0 °C + 1.197 °C" = "31.2 °C"#

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Kai Bowman

To find the final temperature, use the formula:

q = mcΔT

Rearrange the formula to solve for ΔT:

ΔT = q / mc

Plug in the values:

ΔT = (100 J) / (20.0 g * 4.18 J/g°C)

ΔT ≈ 1.196°C

Final temperature = Initial temperature + ΔT

Final temperature ≈ 30.0°C + 1.196°C

Final temperature ≈ 31.2°C

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.