Worksheet: Chemical Formulas

In this worksheet, we will practice writing and interpreting the notations used in molecular and structural formulas.

Q1:

What is the formula for carbon monoxide?

  • A C O 2
  • B C O 2
  • C C O
  • D C O +
  • E C O 3

Q2:

What is the formula of aluminum oxide?

  • A A l O 2 3
  • B A l ( O H ) 2 3
  • C A l O 2
  • D A l ( O H ) 3
  • E A l O

Q3:

What is the formula for aluminum sulfate?

  • A A l ( S O ) 4 3
  • B A l ( S O ) 2 4 3
  • C A l S O 4
  • D A l S O 3
  • E A l ( S O ) 2 3 3

Q4:

What is the formula for iron(III) chloride?

  • A F e C l
  • B F e C l 2
  • C F e C l 3
  • D F e C l 3
  • E F e C l 2 3

Q5:

What is the formula of strontium carbonate?

  • A S r C O 2 3
  • B S r H C O 3
  • C S r ( H C O ) 3 2
  • D S r C O 3
  • E S r ( C O ) 3 2

Q6:

The structural formula of ethanol is as shown.

H C H C H H H O H

Which of the following is a structural isomer of ethanol?

  • A
    H C C H O H H
  • B
    C C H H H H O
  • C
    C H H H O C H H H
  • D
    C H C O H
  • E
    C H O C H H H

Q7:

A magnesium atom has the chemical formula Mg. What is the chemical formula of the magnesium ion?

  • A M g 2 +
  • B M g ( 2 + )
  • C M g +
  • D M g
  • E M g + 2

Q8:

A chlorine atom has the chemical formula Cl. What is the chemical formula of the chloride ion?

  • A C l
  • B C l
  • C C l
  • D C l
  • E C l

Q9:

How many atoms of oxygen are present in the formula 10SO2?

Q10:

What is the chemical formula of dichlorine heptoxide?

  • A 2 C l O 7
  • B C l O 2 7
  • C 2 C l O 7
  • D C l O
  • E C l O 2 6

Q11:

What is the chemical formula of strontium oxide?

  • A S r O
  • B S t O
  • C S r O 2
  • D S t O 2
  • E O S r

Q12:

Which elements are present in a molecule of CO2?

  • ACopper and osmium
  • BCadmium and oxygen
  • CCarbon and oxygen
  • DCobalt
  • ECobalt and osmium

Q13:

How many hydrogen atoms are present in a formula unit of aluminum hydroxide hexahydrate (Al(OH)·6HO)32?

Q14:

What is the chemical formula for a molecule composed of 2 atoms of carbon, 4 atoms of hydrogen, and 1 atom of oxygen?

  • A C H O 2 4 1
  • B C H O 2 4
  • C C H O 2 4
  • D 2 C 4 H 1 O
  • E C H O

Q15:

Which of the following is equivalent to the chemical formula “3CO2”?

  • A3 free carbon atoms and 6 free oxygen atoms
  • B1 molecule of triple carbon dioxide
  • C3 molecules of carbon dioxide
  • D3 dioxycarbon molecules
  • E3 carbon monoxide molecules

Q16:

Electropositive elements are those which lose electrons easily. Elements further to the left or bottom of the Periodic Table are usually more electropositive. In chemical formulas containing more than one element, the more electropositive element is usually written first.

In the chemical formula CO2, is the order of elements correct or incorrect?

  • AIncorrect
  • BCorrect

In the chemical formula CSi, is the order of elements correct or incorrect?

  • ACorrect
  • BIncorrect

In the chemical formula HO2, is the order of elements correct or incorrect?

  • AIncorrect
  • BCorrect

In the chemical formula BF3, is the order of elements correct or incorrect?

  • AIncorrect
  • BCorrect

In the chemical formula GaAs, is the order of elements correct or incorrect?

  • ACorrect
  • BIncorrect

Q17:

How many hydrogen atoms are there in a molecule of methane (CH)4?

Q18:

What is the correct way to write “2 water molecules” using chemical formulas?

  • A H O 2 2 ×
  • B H O 2 2
  • C 2 H O 2
  • D ( H O ) 2 2
  • E 2 H O × 2

Q19:

Fill in the blank: The chemical formula for potassium hexacyanorhodium(III) is .

  • A K [ R h ( C N ) ] 3 6
  • B K [ R h ( C N ) ] 3 6
  • C N a [ R h ( N H ) ] 2 3 6
  • D K [ R h ( C N ) ] 6
  • E N a [ R h ( C N ) ] 2 6

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.