Answer:
C8H17N
Explanation:
Mass of the unknown compound = 5.024 mg
Mass of CO2 = 13.90 mg
Mass of H2O = 6.048 mg
Next, we shall determine the mass of carbon, hydrogen and nitrogen present in the compound. This is illustrated below:
For carbon, C:
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Mass of C = 12/44 x 13.90 = 3.791 mg
For hydrogen, H:
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mass of H = 2/18 x 6.048 = 0.672 mg
For nitrogen, N:
Mass N = mass of unknown – (mass of C + mass of H)
Mass of N = 5.024 – (3.791 + 0.672)
Mass of N = 0.561 mg
Now, we can obtain the empirical formula for the compound as follow:
C = 3.791 mg
H = 0.672 mg
N = 0.561 mg
Divide each by their molar mass
C = 3.791 / 12 = 0.316
H = 0.672 / 1 = 0.672
N = 0.561 / 14 = 0.040
Divide by the smallest
C = 0.316 / 0.04 = 8
H = 0.672 / 0.04 = 17
N = 0.040 / 0.04 = 1
Therefore, the empirical formula for the compound is C8H17N
A large body of matter, anything that takes up space.
Heat, rotating air, and conditions that strengthen that rotation by extending it out along its axis are the ingredients that make fire whirls.
Answer: option A. Cobalt
Explanation:
1) Data:
Q = 1.24 × 10⁶ J
m = 2 kg
Tf = 1768 K
Ti = 298 K
Cs = ?
2) Formula:
Q = m Cs ΔT
ΔT = Tf - Ti = 1,768K - 298K = 1,470K
3) Calculations:
i) Solve for Cs:
Cs = Q / [ m ΔT]
ii) Substitute the data:
Cs = 1.24 × 10⁵ J / [ 2kg (1768K - 298K) ] = 421 J / (kg K)
4) Compare with the specific heats (Cs) of the vaious metals given and you find that it is Cobalt.
