Reaction Types and Balancing

How many oxygen atoms are there in the compound Ca(NO₃)₂?

• 2

• 3

• 6

• 9

Answer explanation

There are 6 oxygen atoms in the compound Ca(NO3)2. Each nitrate (NO3) group contains 3 oxygen atoms, and there are 2 nitrate groups in the compound.

Tags

NGSS.MS-PS1-1

How many nitrogen atoms are in the compound Mg(NO₃)₂?

• 1

• 2

• 3

• 6

Answer explanation

The compound Mg(NO3)2 contains 6 nitrogen atoms. Each nitrate ion (NO3-) contains 1 nitrogen atom, and there are 2 nitrate ions in the compound.

Tags

NGSS.MS-PS1-1

How many nitrogen atoms are there in the compound Al(NO₃)₃?

• 1

• 2

• 3

• 6

Answer explanation

There are 6 nitrogen atoms in the compound Al(NO3)3, which is the correct choice.

Tags

NGSS.MS-PS1-1

How many oxygen atoms are in the compound (NH₄)₂SO₄?

• 1

• 4

• 3

• 2

Answer explanation

The compound (NH4)2SO4 contains 4 oxygen atoms. This is because there are 2 sulfate (SO4) groups, and each group contains 2 oxygen atoms. Therefore, the correct answer is 4.

Tags

NGSS.MS-PS1-1

How many atoms of hydrogen (H) are present in one molecule of glucose (C₆H₁₂O₆)?

• 6

• 12

• 24

• 36

Answer explanation

There are 12 atoms of hydrogen (H) in one molecule of glucose (C6H12O6).

Tags

NGSS.MS-PS1-1

Abril and Brenda are studying a chemical formula. The blue numbers represent ________

• I don't know, and don't want to try

• coefficients

• subscripts

• none of the answers are correct

Answer explanation

The blue numbers in the chemical formula represent subscripts, indicating the number of atoms in a molecule.

Tags

NGSS.MS-PS1-1

The following is what type of reaction:
PbCl₂ + AgNO₃ → Pb(NO₃)₂ + AgCl

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Answer explanation

The given reaction is a double replacement reaction where the cations of two compounds exchange places to form two new compounds. In this case, lead chloride (PbCl2) reacts with silver nitrate (AgNO3) to form lead nitrate (Pb(NO3)2) and silver chloride (AgCl).

Tags

NGSS.MS-PS1-2

The following is what type of reaction:
NH₃ + HCl  → NH₄Cl

• Synthesis

• Decomposition

• Single Replacement Replacement

• Double Replacement Replacement

Answer explanation

The given reaction is a synthesis reaction where NH3 and HCl combine to form NH4Cl.

Tags

NGSS.MS-PS1-2

What type of chemical reaction is this?
Al(OH)₃ → Al₂O₃  + H₂O

• Decomposition

• Combustion

• Synthesis

• Single Replacement 

Answer explanation

This chemical reaction is a decomposition reaction, where Al(OH)3 breaks down into Al2O3 and H2O.

Tags

NGSS.MS-PS1-2

3Ca + 2AlCl₃ --> 3CaCl₂ + 2Al

• Synthesis

• Decomposition

• Single Displacement

• Double Displacement

Answer explanation

In this reaction, a single element (Al) displaces another element (Ca) in a compound. This is known as a single displacement reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5