Answer:
Mass = 0.610 g
Explanation:
Given data:
Mass of Na₂SiO₃ = ?
Mass of HF = 0.800 g
Solution:
Chemical equation:
Na₂SiO₃ + 8HF → H₂SiF₆ + 2NaF + 3H₂O
Number of moles of HF:
Number of moles = mass/ molar mass
Number of moles = 0.800 g/ 20 g/mol
Number of moles = 0.04 mol
Now we will compare the moles of HF and Na₂SiO₃.
HF : Na₂SiO₃
8 : 1
0.04 : 1//8×0.04 = 0.005
Mass of Na₂SiO₃:
Mass = number of moles × molar mass
Mass = 0.005 mol × 122.07 g/mol
Mass = 0.610 g
<u>Answer:</u> The mass of arsenic found in the sample is 0.25 mg
<u>Explanation:</u>
ppm is the amount of solute (in milligrams) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:
Both the masses are in grams.
We are given:
Concentration of arsenic = 5 ppm
Mass of sample = 50 g
Putting values in above equation, we get:
<u>Conversion factor used:</u> 1 g = 1000 mg
Hence, the mass of arsenic found in the sample is 0.25 mg
The answer is that they all have metallic structures
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