Answer:
20.0928.
Explanation:
The average atomic mass is (90 * 19.992 + 10* 21) / 100
= 20.0928.
Answer:
D.
Explanation:
D is the correct answer because, in aqueous solution, solvent is water and solute (in this example carbon dioxide CO₂) is a substance dissolved in water. The amount of solute that can be dissolved in a solvent depends of chemical composition, temperature and pressure
Answer : The percentage composition of carbon, hydrogen and sulfur in a compound is, 38.8 %, 9.6 % and 51.6 % respectively.
Explanation :
To calculate the percentage composition of element in sample, we use the equation:

Given:
Mass of carbon = 1.94 g
Mass of hydrogen = 0.48 g
Mass of sulfur = 2.58 g
First we have to calculate the mass of sample.
Mass of sample = Mass of carbon + Mass of hydrogen + Mass of sulfur
Mass of sample = 1.94 + 0.48 + 2.58 = 5.0 g
Now we have to calculate the percentage composition of a compound.



Hence, the percentage composition of carbon, hydrogen and sulfur in a compound is, 38.8 %, 9.6 % and 51.6 % respectively.
Answer:
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Explanation:
The valency of K element is + 1 while that of PO4 compound is -3
Hence, at least 3 K atoms are needed to combine with PO4 to form K3PO4 compound.
Hence, the revised equation will be
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Now, the number of atoms and charges of each element is a given equation are equal on both the left and right hand side.
Answer:
3.4g of Al
Explanation:
you would need to start with 3.4 g of Al