Q = mcΔt, q = energy [J] m = mass (of water) [g]; c = specific heat capacity of water [J g⁻¹ K⁻¹/°C⁻¹]; Δt = change in temperature [K/°C]
Δt = 121 - -24 = 145
q = 39 × 4.18 × 145
q = 23637.9 J
Answer:
f = 0.6× 10¹⁶ Hz
Explanation:
Given data:
Wavelength of radiation = 5.00 × 10⁻⁸ m
Frequency of radiation = ?
Solution:
Formula:
Speed of light = wavelength × frequency
speed of light = 3 × 10⁸m/s
Now we will put he values in formula.
3 × 10⁸m/s = 5.00 × 10⁻⁸ m × f
f = 3 × 10⁸m/s / 5.00 × 10⁻⁸ m
f = 0.6× 10¹⁶ s⁻¹
s⁻¹ = Hz
f = 0.6× 10¹⁶ Hz
Percent composition by mass of oxygen =
((16.0*6)/(40.1+2*(14.0+16.0*3)))*100%
= 58.5%
therefore, the answer is D
