What does the 2 mean in the formula 5Mg3(PO4)2? There are two elements in magnesium phosphate. There are two molecules of magnes
1 answer:
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Answer:
(a) 3347 J; (b) 3043 J; (c) 58 J/K; (d) 35.5 °C
Explanation:
(a) Heat lost by copper
The formula for the heat lost or gained by a substance is
q =mCΔT
ΔT = T₂ - T₁= 30.3 °C - 100.4 °C = -70.1 °C = -70.1 K
q = 124.0 g × 0.385 J·K⁻¹g⁻¹ × (-70.1 K) = -3347 J
The negative sign shows that heat is lost.
The copper block has lost 3347 J.
(b) Heat gained by water
ΔT = 30.3 °C - 25.1 °C = 5.2 °C = 5.2 K
q = 140.0 g × 4.18 J·K⁻¹g⁻¹ × 5.2 K = 3043 J
The water has gained 3043 J.
(c) Heat capacity of calorimeter
Heat lost by Cu = heat gained by water + heat gained by calorimeter
The temperature change for the calorimeter is the same as that for the water.
ΔT = 5.2 K
The heat capacity of the calorimeter is 58 J/K.
(d) Final temperature of water
The final temperature of the water would be 35.5 °C.
Answer: The atomic weight of the metal would be 85.47.
Explanation:
Mass of isotope 1 of metal = 84.9118
% abundance of isotope 1 of metal = 72.15% =
Mass of isotope 2 of metal= 86.9092
% abundance of isotope 2 of metal = 27.85% =
Formula used for average atomic mass of an element :
Therefore, the atomic weight of the metal would be 85.47.