Answer:
2.2%
Explanation:
Percentage error,
You apply the formula,
[(Estimated value - Actual value)/Actual value] × 100%
; [(43.26 - 42.32)/42.32] × 100
; (0.94/42.32) × 100
; 0.022 × 100
Percent error = 2.2%
Answer:
0.259 kJ/mol ≅ 0.26 kJ/mol.
Explanation:
- To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat absorbed by ice (Q = ??? J).
m is the mass of the ice (m = 100.0 g).
c is the specific heat of water (c of ice = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 21.56°C - 25.0°C = -3.44°C).
<em>∵ Q = m.c.ΔT</em>
∴ Q = (100.0 g)(4.186 J/g.°C)(-3.44°C) = -1440 J = -1.44 kJ.
<em>∵ ΔH = Q/n</em>
n = mass/molar mass = (100.0 g)/(18.0 g/mol) = 5.556 mol.
∴ ΔH = (-1.44 kJ)/(5.556 mol) = 0.259 kJ/mol ≅ 0.26 kJ/mol.
