find weight of the following a) 8 moles of ch4 ,b) 40g molecules of h2no3, c) 1.5* 10 power 25 molecules of so2 ,d) 4.48 litres of o2 gas at Standard temperature and pressure ( STP)
Answers
Answer:Chapter 3: Stoichiometry
Key Skills:
Balance chemical equations
Predict the products of simple combination, decomposition, and combustion reactions.
Calculate formula weights
Convert grams to moles and moles to grams using molar masses.
Convert number of molecules to moles and moles to number of molecules using
Avogadro’s number
Calculate the empirical and molecular formulas of a compound from percentage
composition and molecular weight.
Identify limiting reactants and calculate amounts, in grams or moles, or reactants
consumed and products formed for a reaction.
Calculate the percent yield of a reaction.
Explanation:Answer:
The mole is simply a very large number that is used by chemists as a unit of measurement.
Explanation:
The mole is simply a very large number,
6.022
×
10
23
, that has a special property. If I have
6.022
×
10
23
hydrogen atoms, I have a mass of 1 gram of hydrogen atoms . If I have
6.022
×
10
23
H
2
molecules, I have a mass of 2 gram of hydrogen molecules. If I have
6.022
×
10
23
C
atoms, I have (approximately!) 12 grams.
The mole is thus the link between the micro world of atoms and molecules, and the macro world of grams and litres, the which we can easily measure by mass or volume. The masses for a mole of each element are given on the periodic table as the atomic weight. So, if have 12 g of
C
, I know, fairly precisely, how many atoms of carbon I have. Given this quantity, I know how many molecules of
O
2
are required to react with the
C
, which I could measure by mass or by volume.