Unit 3 Quiz

Q.1

300g of an unkown metal at 400°C is dropped into 500mL of water at 21.5°C. The water is heated up to 74.6°C, what is the heat capacity of the metal?

Substance	Heat Capacity
Iron	0.440
Lithium	3.56
Sodium	1.23
Aluminum	0.900
Potassium	0.75
Lead	0.160
Gold	0.1290

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1.1: Please put answers with 4 sig digs (No UNITS)

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1.2: Based on the chart, what metal is it likely to be (Just the metal)?

Q.2

Hexane combusts completely with oxygen gas.

2.1: What is the balanced equation (NO fractions)?

+-->+

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2.2: What is the enthalpy change (include +/-)(No UNITS)(4 sig digs)?

Substance	ΔHf (kJ/mol)
C6H14	-198.67
O2	0
CO2	−393.5
H2O	-285.8

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2.3: What is the molar enthalpy change of the hexane (include +/-)(No UNITS)(4 sig digs)?

Q.3

3.1: What is the ΔS of this reaction?

2Li_(s) + 2H₂O_(l) = 2LiOH_(aq) + H_2(g)

Chemical	ΔS (J/mol*K)
LiOH	47.97
Li	29.09
H2	130.6
H2O	69.95

Put answers in 4 sig digs

3.2: Is this reaction spontaneous based on entropy alone?