Curriculum
Course: Science — Second Preparatory
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Curriculum

Science — Second Preparatory

Unit 1: Matter and Energy

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Unit 2: Matter and Chemical Reactions

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Unit 3: Energy Flow in Photosynthesis and Respiration

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Unit 4: Geological Processes

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Quiz

The Chemical Equation — Lesson quiz

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  • Questions count: 6
  • Passing grade: 60%
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1.
What does the arrow in a chemical equation show?
That the two sides have equal mass
The direction of the reaction, from reactants to products
The number of atoms in each molecule
Only the gas that is produced
2.
When balancing an equation, which part do we change: the subscripts or the coefficients?
The subscripts only
Both the subscripts and the coefficients
The coefficients only
Neither, we just rewrite the reactants
3.
Balance Mg + O₂ → MgO.
Mg + O₂ → 2MgO
2Mg + 2O₂ → 2MgO
Mg + 2O₂ → MgO₂
2Mg + O₂ → 2MgO
4.
Balance Zn + HCl → ZnCl₂ + H₂.
Zn + 2HCl → ZnCl₂ + H₂
Zn + HCl → ZnCl₂ + H₂
2Zn + HCl → ZnCl₂ + 2H₂
Zn + 2HCl → ZnCl₂ + 2H₂
5.
If 12 g of magnesium burn according to 2Mg + O₂ → 2MgO, how many grams of MgO are formed?
12 g
20 g
24 g
40 g
6.
Balance CH₄ + O₂ → CO₂ + H₂O.
CH₄ + O₂ → CO₂ + H₂O
CH₄ + 2O₂ → CO₂ + H₂O
CH₄ + 2O₂ → CO₂ + 2H₂O
2CH₄ + 4O₂ → 2CO₂ + H₂O
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