Answer:
It is 20. g HF
Explanation:
H2 + F2 ==> 2HF ... balanced equation
Since the question is asking us to find the mass of product formed, we will want to first convert the molecules of H2 into moles of H2 (we could do this at the end of the calculations, but it's just as easy to do it now).
moles of H2 present (using Avogadro's number):
3.0x1023 molecules H2 x 1 mole H2/6.02x1023 molecules = 0.498 moles H2
From the balanced equation, we see that 1 mole H2 produces 2 moles HF. Therefore, we can now find the theoretical mass of HF produced from 0.498 moles H2:
0.498 moles H2 x 2 moles HF/1 mol H2 = 0.996 moles HF formed.
The molar mass of HF = 20.01 g/mole, thus...
0.996 moles HF x 20.01 g/mole = 19.93 g HF = 20. g HF formed (to 2 significant figures)
The atomic mass is the average of the isotopes of the element meaning most averages of isotopes will not be whole numbers
The pressure of the gas is obtained as 48 atm.
<h3>What is the total pressure?</h3>
Now we know that;
Number of moles of CH4 = 48.0 grams /16 g/mol = 3 moles
Number of moles of H2 = 56.0 grams/2 g/mol = 28 moles
Total number of moles present = 3 moles + 28 moles = 31 moles
Using;
PV =nRT
P = total pressure
V = total volume
n = total number of moles
R = gas constant
T = temperature
P = nRT/V
P = 31 * 0.082 * 286/15
P = 48 atm
Learn more about pressure of a gas:brainly.com/question/18124975
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Answer:
Mass = 55.52 g
Explanation:
Given data:
Number of atoms of Li = 4.81×10²⁴ atom
Number of grams = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For Li:
4.81×10²⁴ atom × 1 mol / 6.022 × 10²³ atom
8 moles
Mass in gram:
Mass = number of moles × molar mass
Mass = 8 mol × 6.94 g/mol
Mass = 55.52 g
