Convert 8.2 × 105
cal to kiloJoules.
Answer in units of kJ.
How much energy would be absorbed as heat
by 58 g of iron when heated from 295 K to
307 K?
Answer in units of J.
8.5 calories to kJ.
8.5 calories x 4.182 J/calorie = 35.564 J = 0.035 kJ
To convert 8.2 × 10^5 cal to kilojoules (kJ), use the conversion factor:
1 cal = 4.184 J
1 kJ = 1000 J
First, convert 8.2 × 10^5 cal to joules (J):
8.2 × 10^5 cal * 4.184 J/cal = 3420480 J
Then, convert joules (J) to kilojoules (kJ):
3420480 J / 1000 = 3420.48 kJ
So, 8.2 × 10^5 cal is equal to 3420.48 kJ.
To find the amount of energy absorbed as heat by 58 g of iron when heated from 295 K to 307 K, use the formula:
q = m * c * ΔT
where:
q is the heat energy absorbed,
m is the mass of the substance (in grams),
c is the specific heat capacity of the substance (in J/g•K),
ΔT is the change in temperature (in Kelvin).
The specific heat capacity of iron is typically around 0.45 J/g•K.
Plugging the values into the formula:
m = 58 g
c = 0.45 J/g•K
ΔT = (307 K) - (295 K) = 12 K
q = 58 g * 0.45 J/g•K * 12 K
q = 312.6 J
So, 58 g of iron would absorb 312.6 J of energy as heat when heated from 295 K to 307 K.
To convert from calories (cal) to kilojoules (kJ), you need to know the conversion factor between these units. The conversion factor is 1 cal = 4.184 J, and 1 kJ = 1000 J.
For the first question:
1) Start with the given value: 8.2 × 105 cal.
2) Convert cal to J: Multiply the given value by 4.184 J/cal.
(8.2 × 105 cal) × (4.184 J/cal) = 3.42 × 10^6 J.
3) Convert J to kJ: Divide the obtained value by 1000 J/kJ.
(3.42 × 10^6 J) / (1000 J/kJ) = 3420 kJ.
Therefore, 8.2 × 105 cal is equivalent to 3420 kJ.
For the second question:
1) Start with the given value: 58 g of iron.
2) Calculate the heat absorbed (Q) using the formula:
Q = m × C × ΔT, where
m is the mass (58 g),
C is the specific heat capacity of iron (0.45 J/g°C), and
ΔT is the change in temperature (307 K - 295 K = 12 K).
Q = (58 g) × (0.45 J/g°C) × (12 K) = 313.2 J.
Therefore, 58 g of iron would absorb 313.2 J of heat when heated from 295 K to 307 K.