Answer:
0.19 g
Explanation:
Step 1: Given data
Volume of hydrogen at standard temperature and pressure (STP): 2.1 L
Step 2: Calculate the moles corresponding to 2.1 L of hydrogen at STP
At STP (273.15 K and 1 atm), 1 mole of hydrogen has a volume of 22.4 L if we treat it as an ideal gas.
2.1 L × 1 mol/22.4 L = 0.094 mol
Step 3: Calculate the mass corresponding to 0.094 moles of hydrogen
The molar mass of hydrogen is 2.02 g/mol.
0.094 mol × 2.02 g/mol = 0.19 g
The answer is: [B]: "ionic salt" .
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Note: There is no "sharing of electrons" among the elements in this compound; so this compound in NOT a "covalent molecule".
However, there is ionic bonding: Cu²⁺ and Cl⁻ ; to form: "CuCl₂" .
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Carbonic acid's chemical formula is H2CO3. Its decomposition to water (H2O) and carbon dioxide (CO2) is represented by the equation:
H2CO3(g) → H2O(l) + CO2(g)
% by mass = (mass solute/mass solution)*100%
mass of the solute = 54.7 g
mass of the solution = mass solute + mass solvent=54.7+500=554.7 g
% by mass = (54.7/554.7)*100%≈0.0986*100% = 9.86%
Each carbon atom will react with 4 hydrogen atoms to form methane (
) Since there are 2 hydrogen atoms in a hydrogen molecule (
) then each carbon atom will react with 2 hydrogen molecules. Since there are 22 hydrogen molecules half as many methane molecules will be formed, so 11. Then we can subtract 11 from 34 to find the number of carbon atoms left over.
So in summary, 11 methane molecules will be formed and there will be 23 carbon atoms left over.
