Writing Chemical Equations

The law of conservation of mass states

• chemical reactions create new atoms

• atoms cannot be created or destroyed

• reactants vanish once a reaction takes place

• products appear when a reaction takes place

Tags

NGSS.MS-PS1-5

Which of the following symbols is not a correct indication of the phase of a substance in a reaction? 

• (s)=solid
• (g)=grams
• (l)=liquid
• (aq)= aqueous

Which is the correct chemical equation for the following: Solid Zn reacts with silver (I) chloride to produce Zinc (II) chloride and silver metal

• Zn + AgCl → ZnCl₂ + Ag

• ZnCl₂ + Ag → Zn + AgCl

• ZnCl2 + Ag₂ → Zn + AgCl

• Zn₂Cl + Ag → Zn + AgCl

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which is the correct chemical equation for the following: Barium Chloride combined with sodium sulfide yields barium sulfide and sodium chloride

• BaCl + NaS → BaS+ NaCl

• BaCl₂ + Na₂S → BaS+ NaCl

• BaS+ NaCl → BaCl + NaS

• BaCl₂ + Na₂S → BaS+ NaCl₂

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which is NOT a diatomic molecule?

• Fluorine
• Nitrogen
• Boron
• Bromine

Tags

NGSS.MS-PS1-1

Magnesium can be burned in oxygen to produce solid magnesium oxide.

• Mg(s) + O₂(g)→ MgO(s)

• Mg(s) + O(g) → MgO(s)

• Mg(s) + CO₂(g) → MgO(s) + C(s)

• Mg(s) + O₂(g) → Mg₂O₂(s)

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which compounds are the PRODUCTS of this reaction?

• CO₂ + H₂O

• C₆H₁₂O₆ + O₂

• C₆H₁₂O₆ + CO₂

• H₂O + O₂

Tags

NGSS.MS-PS1-2

NGSS.MS-LS1-6

NGSS.MS-LS1-7

Which are the reactants in the following reaction?

2Mg + O₂ ---> 2MgO

• 2MgO

• 2Mg +O

• 2Mg + O₂

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5