Hydrate Pre-Lab Questions

Name the following hydrate: NaCl • 5H₂O

• sodium chloride

• sodium monochloride pentahydrate

• sodium chloride pentahydrate

• sodium chloride hydrate

State the correct name for the following compound: Cr(NO₃)₃ ⋅ 9H₂O

• chromium nitrate nonahydrate

• chromium (III) nitrate nonahydrate

• chromium nitrogen trioxide nonahydrate

• chromium (I) nitrate heptahydrate

• chromium trinitrate nonahydrate

A 15.67 g sample of a hydrate of magnesium carbonate was heated to drive off the waters of hydration. The mass after heating was reduced to 7.58 g. Calculate the percent water by mass in the original hydrate.

• 7.58 %

• 8.09%

• 48.37%

• 51.63%

What is the correct chemical formula for barium hydroxide octahydrate?

• Ba(OH)₂ . 8H₂O

• Ba(OH)₂ . H₂O

• 8Ba(OH)₂ . H₂O

• Ba . 8(OH)₂

Calculate the percent water by mass in cobalt(II) chloride dihydrate, CoCl₂•2H₂O.

• 36.0%

• 78.3%

• 21.7%

• 10.9%

• 13.9%

A 3.11 g sample of ZnSO₄ ⋅ 7H₂O is heated to dryness. Determine the mass of anhydrous salt remaining after all the water has been driven off.

• 3.11 g

• 1.75 g

• 1.36 g

• 0.562 g

Tags

NGSS.HS-PS1-7

Goggles are worn in the laboratory ____

• to avoid eye strain.

• to improve your vision

• only if you don’t have corrective glasses.

• any time chemicals, heat, or glassware are used.

Long hair in the laboratory must be

• cut short

• held away from the experiment with one hand

• always neatly groomed

• tied back or kept entirely out of the way with a hair band

Which of the following apply when doing lab work?

• long sleeves and loose clothing should be rolled up
• closed toe shoes should be worn
• long hair should be pulled back
• lit Bunsen burners can be left unattended

• safety goggles are optional

Read all procedures thoroughly before entering the laboratory

• True
• False