Answer:
Element Symbol Atomic weight Atoms Mass percent
Carbon C 12.0107 1 23.7894
Hydrogen H 1.00794 3 5.9892
Chlorine Cl 35.453 1 70.2213
Explanation:
Answer:
If we have one mole of water, then we know that it will have a mass of 2 grams (for 2 moles of H atoms) + 16 grams (for one mole O atom) = 18 grams.
Explanation:
Answer:
The metal block had a mass of 1.50kg
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Answer:
frequency = 5.09 × 10^14 Hz
Energy = 3.373 × 10^-19 J
Explanation:
1. The wavelength of a substance is calculated using the formula:
λ = v/f
Where;
λ = wavelength (m)
v = speed of light (m/s)
f = frequency of light (Hz)
According to the information given, λ = 5.89 × 10 −7m, v = 3 × 10^8m/s, f =?
Using λ = v/f
f = v/λ
f = 3 × 10^8 ÷ 5.89 × 10 −7m
f = 0.509 × 10^(8+7)
f = 0.509 × 10^15
f = 5.09 × 10^14 Hz
2. Energy of a photon, E, can be calculated thus:
E = hf
Where;
h = Planck's constant (6.626 × 10^-34 J/s)
f = frequency (Hz)
E = 6.626 × 10^-34 × 5.09 × 10^14
E = 33.726 × 10^(-34+14)
E = 33.726 × 10^(-20)
E = 3.373 × 10^-19 J
The balanced equation for the above reaction is as follows;
Mg + 2HCl ---> MgCl₂ + H₂
stoichiometry of Mg to HCl is 1:2
number of Mg moles reacted - 3.5 mol
1 mol of Mg reacts with 2 mol of HCl
therefore 3.5 mol of Mg requires - 2 x 3.5 = 7.0 mol of HCl
number of HCl moles required to completely react with 3.5 mol of Mg is 7.0 mol of HCl