Answer:
2.04 x 10²⁴ molecules
Explanation:
Given parameters:
Mass of Be(OH)₂ = 145.5g
To calculate the number of molecules in this mass of Be(OH)₂ we follow the following steps:
>> Calculate the number of moles first using the formula below:
Number of moles = mass/molarmass
Since we have been given the mass, let us derive the molar mass of Be(OH)₂
Atomic mass of Be = 9g
O = 16g
H = 1g
Molar Mass = 9 + 2(16 + 1)
= 9 + 34
= 43g/mol
Number of moles = 145.5/43 = 3.38mol
>>> We know that a mole is the amount of substance that contains Avogadro’s number of particles. The particles can be atoms, molecules, particles etc. Therefore we use the expression below to determine the number of molecules in 3.38mol of Be(OH)₂:
Number of
molecules= number of moles x 6.02 x 10²³
Number of molecules= 3.38 x 6.02 x 10²³
= 20.37 x 10²³ molecules
= 2.04 x 10²⁴ molecules
Answer: SO2
Explanation: quizlet has flash cards on it
the Percentage yield for the reaction = 48.8%
What is Percentage yield ?
The % ratio of the theoretical yield to the actual yield is known as the percent yield. It is calculated as the theoretical yield multiplied by 100% divided by the experimental yield. The percent yield is 100% if the theoretical and actual yields are equal. Because the real yield is frequently lower than the theoretical value, percent yield is typically lower than 100%. This may be due to incomplete or conflicting reactions or sample loss during recovery. If the percent yield is more than 100%, more sample than expected was retrieved from the reaction.
4 P + 3 O2 = P4O6
moles P = 75.3 g / 30.9738 g/mol= 2.43
moles O2 required = 2.43 x 3 / 4=1.82
actual moles O2 = 38.7 g /32 g/mol=1.21 so O2 is the limiting reactant
theoretical moles P4O6 = 1.21 / 3=0.403
theoretical mass P4O6 = 0.403 mol x 219.895 g/mol=88.6 g
% yield = 43.3 x 100/ 88.6 = 48.8 %
the Percentage yield for the reaction = 48.8%
To know about Percentage yield from the link
brainly.com/question/8638404
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<span>Ionic compounds
Hope this helps! :)</span>