Answer:
7.51 × 10¹⁷
Explanation:
1. Calculate the <em>energy of one photon</em>
The formula for the energy of a photon is
E = hc/λ
h = 6.626 × 10⁻³⁴ J·s; c = 2.998 × 10⁸ m·s⁻¹
λ = 531 nm = 531 × 10⁻⁹ m Insert the values
E = (6.626 × 10⁻³⁴ × 2.998× 10⁸)/(531 × 10⁻⁹)
E = 3.741× 10⁻¹⁹ J
===============
2. Calculate the number of photons
Divide the total energy by the energy of one photon.
No. of photons = 0.281 × 1/3.741 × 10⁻¹⁹
No. of photons = 7.51 × 10¹⁷ photons
Answer:
No pressure will change in the chamber at reactions end
Explanation:
CH4 + 2O2 ---> CO2 + 2H2O
According the above reaction
There are 3 moles total of gaseous reactants, and 3 moles total of gaseous products, so this reaction results in no change of volume. Therefore, since this happens at constant volume and constant temperature, the pressures are directly related to the moles used and produced. This way, no pressure will change in the chamber at reactions end
Answer:
D) all of the above
Explanation:
<em>Which of the following represents 1 mol of phosphine gas, PH₃? </em>
<em>A) 6.02 x 10²³ phosphine molecules.</em> YES. Considering Avogadro's number, 1 mole of a substance contains 6.02 x 10²³ molecules of such substance.
<em>B) 34.00 g phosphine gas.</em> YES. The molar mass of phosphine is equal to the sum of the molar masses of the elements that form it.
MM(PH₃) = MM(P) + 3 × MM(H) = 31.00 g/mol + 3 × 1.00 g/mol = 34.00 g/mol.
<em>C) 22.4 L phosphine gas at STP.</em> YES. At standard temperature (0 °C) and pressure (1 atm), 1 mole of any gas occupies a volume of 22.4 L.
Answer:- Formula of the hydrate is and it's name is Iron(III)sulfate pentahydrate.
Solution:- As per the given information, there is 18.4% water in the hydrate. If we assume the mass of the hydrate as 100 grams then there would be 18.4 grams of water and 81.6 grams of Iron(III)sulfate present in the hydrate.
Molar mass for Iron(III)sulfate is 399.88 gram per mol and the molar mass for water is 18.02 gram per mol.
We will calculate the moles of Iron(III)sulfate and water present in the compound on dividing their grams by their molar masses as:
=
=
Now, the next step is to calculate the mol ratio and for this we divide the moles of each by the least one of them means whose moles are less. Here, the moles of Iron(III)sulfate are less than moles of water. So, we divide the moles of each by 0.204.
= 1
= 5
There is 1:5 mol ratio between Iron(III)sulfate and water. So, the formula of the hydrate is and the name of the hydrate is Iron(III)sulfate pentahydrate.