What is the concentration in molarity of a solution that has 54.21g of calcium hydroxide dissolved in 560mL of water?
1 answer:
We know that Molarity = # mol/L
In the question, we are given grams - so we need to calculate the number of moles that we are dealing with. We can do this by first finding out what the molecular formula of calcium hydroxide is:
This means that we have 1 calcium and 2 hydroxides.
We can find the number of moles by taking the grams given divided by the molar mass of the molecule. We can find the molar mass of the molecule by taking each atomic mass of each atom (found on the periodic table) and adding them together:
Ca = 40.08g
O = 15.999g
H = 1.008g
We have 1 calcium, 2 oxygens, and 2 hydrogens. So let's add the atomic masses together:
40.08 + 2(15.999) + 2(1.008) = 74.094g
Now that we have the molar mass, we can find the number of moles due to already knowing the given amount in the question:
54.21g/74.09g = 0.73 moles of
Now that we know the number of moles, we can solve for the molarity; The other part of the question gives us 560 mL of water - but this can quickly be converted to liters by moving the decimal to the left 3 places => 0.560 L
Knowing all of this information, we can plug it into the molarity equation:
Molarity = 0.73 mol/0.56 L
Molarity = 1.30
The molarity of the solution is 1.3 M.
In the question, we are given grams - so we need to calculate the number of moles that we are dealing with. We can do this by first finding out what the molecular formula of calcium hydroxide is:
This means that we have 1 calcium and 2 hydroxides.
We can find the number of moles by taking the grams given divided by the molar mass of the molecule. We can find the molar mass of the molecule by taking each atomic mass of each atom (found on the periodic table) and adding them together:
Ca = 40.08g
O = 15.999g
H = 1.008g
We have 1 calcium, 2 oxygens, and 2 hydrogens. So let's add the atomic masses together:
40.08 + 2(15.999) + 2(1.008) = 74.094g
Now that we have the molar mass, we can find the number of moles due to already knowing the given amount in the question:
54.21g/74.09g = 0.73 moles of
Now that we know the number of moles, we can solve for the molarity; The other part of the question gives us 560 mL of water - but this can quickly be converted to liters by moving the decimal to the left 3 places => 0.560 L
Knowing all of this information, we can plug it into the molarity equation:
Molarity = 0.73 mol/0.56 L
Molarity = 1.30
The molarity of the solution is 1.3 M.
You might be interested in
A dipeptide is formed when 2 amino acids are joined together by a peptide linkage.
Each amino acid molecule contains an amino group ( -NH₂) and a carboxyl ( -COOH) group. During peptide formation, a carboxyl group of one amino acid reacts with amino group of the other , resulting in the formation of a linkage known as "peptide linkage". A water molecule is also eliminated in this reaction.
A general peptide formation reaction can be written as
In the above reaction, we can see a peptide linkage ( -CONH-) getting formed between 2 amino acid molecules.
In the given molecule the peptide linkage is shown by drawing a box around it. Please refer to the attached image.
If we want to know the amino acid molecules from which this peptide is formed, we will simply break the CO-NH bond.
We will add -OH group to CO part and -H to NH part to get 2 amino acid molecules as shown in the picture.
The two amino acids thus formed are Serine & Cysteine.
Serine is designated as "Ser" and Cysteine is designated as "Cys"
Therefore the given dipeptide is designated as "Ser-Cys"
