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Some do not exist as individual molecules. For example, there is no such thing as a molecule of sodium chloride. That's why it is appropriate to use the term formula weight for this type of compound. However, some compounds do exist as individual molecules. For example, water,carbon-dioxide etc. So it is appropriate to use the term molecular weight for it.
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The molecular formula of lithium carbonate is Li2CO3. What is the molecular weight of this drug?
As you know this salt is commonly used to treat mania. The formula mass is simply the sum of the molar masses of the contributing atoms: i.e. $(2xx6.94+12.011+3xx15.999)*g*mol^-1$ $=$ $??$
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The molecular formula of calcium chloride is CaCl2. What is the molecular weight of this drug?
Weight of $Ca$ = $40$ Weight of $Cl$ = $35.5$ Molecular formula is $CaCl_2$ i.e. $1$ atom of $Ca$ and $2$ atoms of $Cl$. Hence, molecular weight = $"1...
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How do we differentiate between a $"molecular element"$, and a $"molecular compound"$? And how are these differentiated from $"non-molecular"$ species?
The distinction between a molecular and non-molecular structure is one of the most important criteria with which to assess . But here, if we have an elemental molecule, we have...
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A carbon compound contains 12.8% of carbon, 2.1% of hydrogen and 85.1% of bromine. The molecular weight of the compound is 187.9. What is the molecular formula of the compound?
(Atomic weight: H = 1.008, C = 12.0, Br = 79.9)
As always with these problems, it is useful to assume $100*g$ of unknown compound....and thus find an empirical formula... $"Moles of carbon"=(12.8*g)/(12.011*g*mol^-1)=1.066*mol.$ $"Moles of hydrogen"=(2.1*g)/(1.00794*g*mol^-1)=2.084*mol.$ $"Moles of bromine"=(85.1*g)/(79.90*g*mol^-1)=1.066*mol.$ And we...
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If the empirical formula is $C_2H_5$, and the molecular mass is $58*g*mol^-1$, what is the molecular formula?
Butane is a $C_4$ alkane. The isomer depicted is the straight chain, n -butane. It has 1 other isomer.
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Vitamin C has a empirical formula of C3H4O3 and a molecular mass of 176 amu, what is its molecular formula?
Them molecular formula is found by: $("Empirical formula")_n$ where, $n=(MM)/(e.f.m.)$ and $e.f.m.$ is the empirical formula mass. $n=(176)/(88)=2$ Therefore, the molecular formula is $C_6H_8O_6$
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What is the molecular formula of dichloroacetic acid if the emperical formula is CHOCl and the gram molecular mass is 129.0 g?
So, $(CHOCl)xxn$ $=$ $MF$; i.e. $(12.011 + 1.00794 + 15.999 + 35.45)xxn*g*mol^-1 = 129.0*g*mol^-1$. Clearly $n=2$. The molecular formula, a multiple of the empirical formula, is $C_2H_2Cl_2O_2$, or rather $Cl_2CH-C(=O)OH$.
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An unknown sample with a molecular mass of 180.0g is analyzed to yield 40% C, 6.7% H, and 53.3% O. What is the empirical formula and the molecular formula of this compound?
We assume $100*g$ of compound and work out the atomic proportions: $C: (40.0*g)/(12.011*g*mol^-1)$ $=$ $3.33$ $mol$. $H: (6.7*g)/(1.0794*g*mol^-1)$ $=$ $6.65$ $mol$. $O: (53.3.0*g)/(15.999*g*mol^-1)$ $=$ $3.31$ $mol$. We divide thru by...
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Determine the molecular formula of a hydrocarbon if the combustion of 5.3 mg obtained 16.6 mg $"CO"_2$. The density of the gas at standard conditions is $"2.504 g/dm"^3$. What is the molar mass of the gas and its molecular and empirical formula?
Original question stated student mentioned that the question used 6.48 mg of carbon dioxide, as opposed to 8.48 mL. Solution with revised inputs from student. All things same except...
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Hydrogen peroxide has the empirical formula HO and an empirical formula weight of 17.0 amu. If the molecular weight is 34.0 amu, what is the molecular formula?
First, you want to find the ratio between the empirical formula and molecular formula; that is, how much has the molecular formula been simplified to reach the empirical formula. We...
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