a gaseous compound of carbon and hydrogen contains 80% carbon by mass, one dm3 of the compound at s.t.p weighing 1.35g. calculate

To calculate the molar mass and molecular formula of the compound, we need to follow these steps:

1. Calculate the number of moles of the compound:
Number of moles = mass / molar mass

2. Determine the number of moles of carbon:
Moles of carbon = mass of carbon / molar mass of carbon

3. Determine the number of moles of hydrogen:
Moles of hydrogen = mass of hydrogen / molar mass of hydrogen

4. Calculate the proportion of carbon and hydrogen atoms in the compound:
Proportion of carbon = moles of carbon / (moles of carbon + moles of hydrogen)
Proportion of hydrogen = moles of hydrogen / (moles of carbon + moles of hydrogen)

5. Divide the proportion of carbon and hydrogen by the smallest proportion to get the simplest whole-number ratios of carbon and hydrogen atoms.
Simplest ratio of carbon atoms = Proportion of carbon / smallest proportion
Simplest ratio of hydrogen atoms = Proportion of hydrogen / smallest proportion

6. Multiply the simplest ratio by a common multiple to get whole numbers if necessary.

Let's start by calculating the molar mass of the compound.

Given:
- Mass of the compound = 1.35 g
- Volume of the compound = 1 dm^3

Step 1: Calculate the number of moles of the compound.
Number of moles = mass / molar mass
Number of moles = 1.35 g / molar mass

Since the compound contains 80% carbon by mass, we can determine the mass of carbon and hydrogen separately.
Mass of carbon = 80% of 1.35 g = 0.8 * 1.35 g
Mass of carbon = 1.08 g (rounded to two decimal places)

Mass of hydrogen = 20% of 1.35 g = 0.2 * 1.35 g
Mass of hydrogen = 0.27 g (rounded to two decimal places)

Step 2: Determine the number of moles of carbon.
Moles of carbon = mass of carbon / molar mass of carbon
Moles of carbon = 1.08 g / molar mass of carbon

Step 3: Determine the number of moles of hydrogen.
Moles of hydrogen = mass of hydrogen / molar mass of hydrogen
Moles of hydrogen = 0.27 g / molar mass of hydrogen

Step 4: Calculate the proportion of carbon and hydrogen atoms in the compound.
Proportion of carbon = moles of carbon / (moles of carbon + moles of hydrogen)
Proportion of hydrogen = moles of hydrogen / (moles of carbon + moles of hydrogen)

Step 5: Divide the proportion of carbon and hydrogen by the smallest proportion to get the simplest whole-number ratios of carbon and hydrogen atoms.
Simplest ratio of carbon atoms = Proportion of carbon / smallest proportion
Simplest ratio of hydrogen atoms = Proportion of hydrogen / smallest proportion

Step 6: Multiply the simplest ratio by a common multiple to get whole numbers if necessary.

Unfortunately, we cannot proceed with the calculation as the molar masses of carbon and hydrogen are not provided. Could you please provide the molar masses of carbon and hydrogen?

To calculate the mass of carbon in the gaseous compound, we can use the following steps:

1. Determine the mass of the compound: Given that 1 dm^3 of the compound at standard temperature and pressure (STP) weighs 1.35g.

2. Calculate the mass of carbon in the compound: Since the compound contains 80% carbon by mass, multiply the total mass of the compound by 0.8.

Let's plug in the values and perform the calculations:

1. Mass of the compound: 1.35g

2. Mass of carbon = Mass of the compound × Percentage of carbon / 100
Mass of carbon = 1.35g × 80 / 100
Mass of carbon = 1.08g

Therefore, the mass of carbon in the gaseous compound is 1.08g.

calculate what?

assume you have 100 grams.

then 80 grams is carbon, or 80/12 moles
and 20 grams is H, or 20/1 moles H

C=80/12=6.66 moles
H= 20

divide each by the lowest
C=1
H=3 empirical formula: CH3

Now, 22.4 liters has a mass of 1.35*22.4 = 30.24grams
divide that by the empirical mass
30.24/15=2
Molecular formula: twice the empirical formula, or C2H6

Your instructor is just too easy.