Answer:
D
Explanation:
that should be the answer
the answer is b it is composed of protons and neutrons.
hope this helped
When you pack down snow into ice the snow hardens and some times turns into an icicle
Answer:
0.0329g of quinine
Explanation:
If 25.0ppm of quinine solution had a fluorescence of 193, the solution that had a fluorescence of 127 has as concentration:
127 × (25.0ppm / 193) = <em>16.45ppm</em>
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As the solution was diluted from 50.0mL to 200.0mL, the sample tonic of water contains:
16.45ppm × (200.0mL / 50.0mL) = 65.8 ppm
As the original solution contains 500.0mL, mass of quinine is:
0.5000L × (65.8mg / L) = 32.9mg ≡<em> 0.0329g of quinine</em>
Answer: D.Aluminium Oxide 0.10, Magnesium Oxide 0.50
Explanation:
Number of moles of NaOH= number of moles × volume
Number of moles= 100/1000 × 2 = 0.2 moles
Since;
2 moles of NaOH yield 1 mole of Al2O3
0.2 moles of NaOH will yield 0.2 × 1/2 = 0.1 moles of Al2O3.
Number of moles of HCl= 800/1000 × 2 = 1.6 moles
If 1 mole of Al2O3 requires 6 moles of HCl
0.1 moles of Al2O3 requires 0.1 × 6 = 0.6 moles of HCl.
Number of moles of HCl left after reaction with Al2O3 = 1.6- 0.6 = 1 mole
This leftover reacts with MgO
But;
1 mole of MgO reacts with 2 moles of HCl
x moles of MgO reacts with 1 mole of HCl
Thus; x= 0.5 moles of MgO