Answer:
C. Boiling water
Explanation:
Boiling water is a physical change only; the H20 molecules are moving from a liquid state to a gas state and not turning into a new substance.
<span>C. Their direction of motion is south and north. </span>
Given:
Iron, 125 grams
T
1 = 23.5 degrees Celsius, T2 =
78 degrees Celsius.
Required:
Heat produced in kilojoules
Solution:
The molar mass of iron is 55.8
grams per mole. SO we need to change the given mass of iron into moles.
Number of moles of iron = 125 g/(55.8
g/mol) = 2.24 moles
<span>
Q (heat) = nRT = nR(T2 = T1)</span>
Q (heat) = 2.24 moles (8.314
Joules per mol degrees Celsius) (78.0 degrees Celsius – 23.5 degrees Celsius)
<u>Q (heat) = 1014.97 Joules or
1.015 kilojoules</u>
<span>This is the amount of heat
produced in warming 125 g f iron.</span>
First, we need to transform km to meters.
1 km = 1000 meters
2.6 * 1000 = 2600
Now, there are 7 days in a week.
Multiply.
2600 * 7 = 18,200
Final answer: 18,200 meters a week
