Question

study the data table.
which system produced the most thermal energy?
sodium carbonate in water.
magnesium sulfate in water.
calcium chloride in water.
ammonium chloride in water.

compound

$t_i$ (initial temp)

$t_f$ (final temp)

$delta t$ (change in temp)

cost (per 30g container)

safety (msds health warning)

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magnesium sulfate

$23^circ c$

$30^circ c$

$+7^circ c$

$16.20

1

calcium chloride

$23^circ c$

$33^circ c$

$+10^circ c$

$4.25

2 (if ingested)

sodium carbonate

$22^circ c$

$24.4^circ c$

$+2.4^circ c$

$3.95

2 (if ingested)

ammonium chloride

$22^circ c$

$19^circ c$

$-3^circ c$

$4.35

2 (if eye contact or ingested)

Explanation:

Thermal energy released in a dissolution system is indicated by a positive temperature change (ΔT), where a larger ΔT means more thermal energy produced. Compare the ΔT values of each option: Magnesium sulfate (+7°C), Calcium chloride (+10°C), Sodium carbonate (+2.4°C), Ammonium chloride (-3°C, absorbs energy). Calcium chloride has the largest positive ΔT.

Answer:

Calcium chloride in water.