Combustion is a reaction between a combustible substance and oxygen, to ultimately produce carbon dioxide and water. Reaction between carbon and oxygen would give,
C + O2 ------> CO2
Here, we have 86.5 grams of carbon dioxide, CO2, which is a product of combustion. Dividing this mass by the molar mass of CO2, which is 44 grams, we can determine the number of moles of CO2.
<u> 86.5 g CO </u> = 1.966 moles CO2
44 g CO2/ mole
Considering that CO2 is composed of 1 mole of carbon and 2 moles of oxygen, and that with complete combustion, 1 mole of carbon reacts to produces 1 mole of CO2, we can then determine the mass of the carbon in the hydrocarbon fuel.
1.966 moles CO2 x <u> 1 mole C </u> x <u> </u><u>12 g C </u> = 23.59 g C
1 mole CO2 1 mole C
We were given 25.0 grams of the fuel hydrocarbon. A hydrocarbon is a substance consisting of carbon and hydrogen. To determine the mass of the hydrogen in the fuel, we simply subtract 23.59 grams from 25.0 grams.
25.0 g - 23.59 g = 1.41 grams Hydrogen
To know the number of moles of hydrogen, we divide the mass of the hydrogen in the fuel by the molar mass of hydrogen, which is 1.01 g/mole. Thus, we have 1.396 mole hydrogen.
To determine the empirical formula, we divide the number of moles carbon by the number of moles hydrogen, and find a factor that would give whole number ratios for the carbon and hydrogen in the fuel,
Carbon: <u> 1.966 mol </u> = 1.408 x 5 (factor) = 7
1.396 mol
Hydrogen: <u> 1.396 mol </u> = 1.00 x 5 (factor) = 5
1.396 mol
Thus, the empirical formula is C7H5
a. We first calculate the moles of sucrose needed
moles sucrose = 0.250 M * 0.25 L
moles sucrose = 0.0625 mol
The molar mass of sucrose 342.3 g/mol, so the mass of
sucrose needed is:
mass sucrose = 0.0625 mol * 342.3 g/mol
mass sucrose = 21.4 grams
So simply dissolved about 21.4 grams of sucrose in 250 mL
solution.
b. We use the formula:
M1 V1 = M2 V2
1.50 M * V1 = 0.100 M * 0.350 L
V1 = 0.0233 L = 23.3 mL
So simply take 23.3 mL of solution from 1.50 M then dilute
it with water until 350 mL to make 0.100 M.
First Rusting is slow oxidation of iron into iron oxide using H2O and oxygen in atmosphere which is a chemical reaction.
burning is also a oxidation but kinda fast using oxygen in atmosphere to oxidize the hydrocarbon(paraffin wax) in candle to give heat and CO2.
So they are both chemical reactions which happens at different rate.
Answer:
yes it is true
Explanation:
evaporation occurs when burning liquid water changes into gas.
Answer:
New cells arise from existing cells.
Explanation:
According to the cell theory, "all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells"(Lumen Learning).
Cells are the basic unit of life. Some organisms consists of only one cell while other organisms have many cells and are called multicellular organisms.
In multicellular organisms, new cells are formed by the division of preexisting cells.
