# Question fae85

Jun 14, 2017

The rates are 1.4 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1", 1.3 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1", and 1.0 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1", respectively.

#### Explanation:

The formula for the rate is

color(blue)(bar(ul(|color(white)(a/a)"rate" = "-"(Δ["N"_2"O"_5])/(Δt) = "-"(["N"_2"O"_5]_2 - ["N"_2"O"_5]_1)/(t_2 - t_1)color(white)(a/a)|)))" "

0 s to 195 s

$\text{rate" = "-"("2.10 mol/L - 2.37 mol/L"/("195 s - 0 s")) = -("-0.27 mol/L")/"195 s}$

= 1.4 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1"

195 s to 416 s

$\text{rate" = "-"("1.82 mol/L - 2.10 mol/L"/("416 s - 195 s")) = -("-0.28 mol/L")/"221 s}$

= 1.3 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1"

416 s to 725 s

$\text{rate" = "-"("1.50 mol/L - 1.82 mol/L"/("725 s - 416 s")) = -("-0.32 mol/L")/"309 s}$

= 1.0 × 10^"-3"color(white)(l) "mol·L"^"-1""s"^"-1"#

Note: The data justify only two significant figures.

You may have to recalculate if Sapling expects three significant figures.