Unit 4.6 Mixtures & Gravimetric analysis

What is the first step of Gravimetric analysis?

• Dissolve unknown substance in water

• Filter and dry precipitate

• React unknown with known substance to form a precipitate

• None of the above

What is the analytic technique that uses the measurement of mass?

• Evaporation

• Gravimetric analysis

• Isolation analysis

• Infrared Spectroscopy

Gravimetric analysis is usually applied to Ionic compounds.

• TRUE

• FALSE

I am a species that contains molecules of only a signle type. I am a….

• Pure substance

• Mixture

• Solution

• Heterogeneous mixture

Look at the image, this is a...

• Pure substance

• Mixture

• Metal compound

• Benzene

Look at the image, this is a...

• Pure substance

• Mixture

• Homogenous mixture

• Covalent compound

H₂O has a molar mass of 18g/mol

Oxygen has a molar mass of 16g/mol

What is the percent by mass of Oxygen?

• 2%

• 8.8%

• 25.8%

• 88.8%

The molar mass of NO2 is 46 g/mol

Nitrogen has a molar mass of 14 g/mol

What is the percent by mass of Nitrogen?

• 3%

• 13%

• 30.4%

• 69.5%

If I find a chemical to be 42.5% by mass, what is this as a decimal to be able to multiple with it.

• 0.00425

• 0.0425

• 0.425

• 4.25

In an experiment it is found that we have 0.425g of Cl in MgCl, the total mass of the sample was 1.152g.

What is the mass percent of Cl in the sample?

• 3.6%

• 21.5%

• 36.89%

• 38.98%