What is always conserved in both physical and chemical changes, explain?
1 answer:
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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.
Answer: The empirical formula is .
Explanation:
The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:
where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.
We are given:
Mass of = 12.24 g
Mass of = 2.505 g
Molar mass of carbon dioxide = 44 g/mol
Molar mass of water = 18 g/mol
For calculating the mass of carbon:
In 44g of carbon dioxide, 12 g of carbon is contained.
So, in 12.24 g of carbon dioxide, = of carbon will be contained.
For calculating the mass of hydrogen:
In 18g of water, 2 g of hydrogen is contained.
So, in 2.505 g of water, = of hydrogen will be contained.
Mass of oxygen in the compound = (5.287) - (3.338+0.278) = 1.671 g
Step 1 : convert given masses into moles.
Moles of C =
Moles of H=
Moles of O=
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =
For H =
For O =
The ratio of C : H : O = 3: 3: 1
Hence the empirical formula is .