Answer:
62.98 % of the sample of hydrate is water
Explanation:
Step 1: Data given
Mass of the sample of a hydrate of sodium carbonate (Na2CO3) = 2.026 grams
After heating, the mass of the sample is 0.750 g
Molar mass H2O = 18.02 g/mol
Step 2: Calculate mass of water
Mass water = mass of hydrate - mass of sample after heating
Mass water = 2.026 grams - 0.750 grams
Mass water = 1.276 grams
Step 3: Calculate mass % percent of water
Mass % of water = (mass of water / total mass hydrate) * 100 %
Mass % of water = (1.276 grams / 2.026 grams) *100 %
Mass % of water = 62.98 %
62.98 % of the sample of hydrate is water
Answer:
A
Explanation:
The answer A is the best answer because it contains the most general characteristic of a chemical change.
Answer:
[H₃O⁺] = 0.05 M & [OH⁻] = 2.0 x 10⁻¹³.
Explanation:
- HNO₃ is completely ionized in water as:
<em>HNO₃ + H₂O → H₃O⁺ + NO₃⁻.</em>
- The concentration of hydronium ion is equal to the concentration of HNO₃:
[H₃O⁺] = 0.05 M.
∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
<em>∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] </em>= 10⁻¹⁴/0.05 = <em>2.0 x 10⁻¹³.</em>
Answer:
a resource that cannot be replenished in a short period of time.
Explanation:
Nonrenewable energy sources take thousands to millions of years to replenish. hence the "nonrenewable".
Answer:
5.72 g ( 1 mol / 180.16 g ) ( 6.022 x 10^23 molecules / mole ) = 1.90x10^23 molecules