All categories

3 years ago

How much heat is absorbed when 4.5g of ice at 0°C melts to water at 10°C?

Chemistry

1 answer:

atroni [7]3 years ago

5 0

Answer: 90.45 joules

Explanation:

The quantity of Heat Energy (Q) absorbed by ice depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)

Thus, Q = MCΦ

In this case,

Q = ?

Mass of ice = 4.5g

C = 2.010 J/g°C (Though not provided, but the specific heat capacity of ice is 2.010 J/g°C)

Φ = (Final temperature - Initial temperature)

= 10°C - 0°C = 10°C

Then, Q = MCΦ

Q = 4.5g x 2.010 J/g°C x 10°C

Q = 90.45 joules

Thus, 90.45 joules of heat is absorbed by ice.

You might be interested in

Which of these common substances is a mixture?

ivolga24 [154]

B .pure water it’s made up of oxygen and hydrogen “H2O”

5 0

2 years ago

Read 2 more answers

Suppose you have just added 100 ml of a solution containing 0.5 mol of acetic acid per liter to 400 ml of 0.5 m naoh. what is th

Tpy6a [65]

$pH = 13.5$

Explanation:

Sodium hydroxide completely ionizes in water to produce sodium ions and hydroxide ions. Hydroxide ions are in excess and neutralize all acetic acid added by the following ionic equation:

$\text{HAc} + \text{OH}^{-} \to \text{Ac}^{-} + \text{H}_2\text{O}$

The mixture would contain

$0.4 \times 0.5 - 0.1 \times 0.5 = 0.15 \; \text{mol}$ of $\text{OH}^{-}$ and
$0.1 \times 0.5 = 0.05 \; \text{mol}$ of $\text{Ac}^{-}$

if $\text{Ac}^{-}$ undergoes no hydrolysis; the solution is of volume $0.1 + 0.4 = 0.5 \; \text{L}$ after the mixing. The two species would thus be of concentration $0.30 \; \text{mol} \cdot \text{L}^{-1}$ and $0.10 \; \text{mol} \cdot \text{L}^{-1}$ , respectively.

Construct a RICE table for the hydrolysis of $\text{Ac}^{-}$ under a basic aqueous environment (with a negligible hydronium concentration.)

$\begin{array}{cccccccc} \text{R} & \text{Ac}^{-}(aq) &+ & \text{H}_2\text{O}(aq) & \leftrightharpoons & \text{HAc}(aq) & + & \text{OH}^{-} (aq)\\ \text{I} & 0.10 \; \text{M} & & & & & &0.30 \; \text{M}\\ \text{C} & -x \; \text{M}& & & & +x \; \text{M}& & +x \; \text{M} \\ \text{E} & (0.10 - x) \; \text{M} & & & & x \; \text{M} & & (0.30 +x) \; \text{M} \end{array}$

The question supplied the acid dissociation constant $pK_a$ for acetic acid $\text{HAc}$ ; however, calculating the hydrolysis equilibrium taking place in this basic mixture requires the base dissociation constant $pK_b$ for its conjugate base, $\text{Ac}^{-}$ . The following relationship relates the two quantities:

$pK_{b} (\text{Ac}^{-}) = pK_{w} - pK_{a}( \text{HAc})$

... where the water self-ionization constant $pK_w \approx 14$ under standard conditions. Thus $pK_{b} (\text{Ac}^{-}) = 14 - 4.7 = 9.3$ . By the definition of $pK_b$ :

$[\text{HAc} (aq)] \cdot [\text{OH}^{-} (aq)] / [\text{Ac}^{-} (aq) ] = K_b = 10^{-pK_{b}}$

$x \cdot (0.3 + x) / (0.1 - x) = 10^{-9.3}$

$x = 1.67 \times 10^{-10} \; \text{M} \approx 0 \; \text{M}$

$[\text{OH}^{-}] = 0.30 +x \approx 0.30 \; \text{M}$

$pH = pK_{w} - pOH = 14 + \text{log}_{10}[\text{OH}^{-}] = 14 + \text{log}_{10}{0.30} = 13.5$

6 0

2 years ago

Question 5 of 5

rjkz [21]

Probably Fresh vegetables, it can rot out, that’d be my guess, it’s not canned

8 0

2 years ago

Read 2 more answers

An aluminum sample has a mass of 80.1 g and a density of 2.70g/cm3 . According to the date to what number of significant figures

DIA [1.3K]

80.1 g* (1 cm^(3)/ 2.70 g)= 29.666666... cm^(3).

The calculated volume should have 3 significant figures, so the final answer is 2.97*10^(1) cm^(3)

Hope this helps~

3 0

3 years ago

Read 2 more answers

S SIO₂ +3C Sic +20o Sic ? mass in grams С c-

seraphim [82]

Answer:

26.74g

Explanation:

The equation of the reaction is;

SIO₂ + 3C --> SiC +2CO

From the balanced equation, the relationship between SiC and C is;

3 mol of C produces 1 mol of SiC

Converting mol to mass using; Mass = moles * Molar mass

Mass of SiC = 1 mol * 40.11 g/mol = 40.11g

This means;

3 mol of C produces 40.11g of SiC

2 mol of C produces xg of SiC

3 = 40.11

2 = x

x = 2 * 40.11 / 3 = 26.74g

6 0

2 years ago