Day 8 Law of conservation of Mass

The elements represented in the chemical equation are:

• Hydrogen and Oxygen

• Carbon and Nitrogen

• Sodium and Chlorine

• Calcium and Sulfur

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-1

Label the reactants and products in the given diagram.

• Reactants are on the left, products are on the right.

• Reactants are on the right, products are on the left.

• Both reactants and products are on the left.

• Both reactants and products are on the right.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

A diagram is used to represent a chemical equation for the reaction that produces water. The law of conservation of mass can be observed in the diagram. In the tables, record the symbols and number of atoms that represent the elements in the diagram.

• Hydrogen: H, 2 atoms; Oxygen: O, 2 atoms; Water: H2O, 2 H atoms and 1 O atom (per molecule, but 2 H2O molecules for balance: 4 H, 2 O)

• Hydrogen: H, 1 atom; Oxygen: O, 2 atoms; Water: H2O, 2 H atoms and 2 O atoms (per molecule)

• Hydrogen: H, 2 atoms; Oxygen: O, 1 atom; Water: H2O, 2 H atoms and 1 O atom (per molecule, but 1 H2O molecule for balance: 2 H, 1 O)

• Hydrogen: H, 4 atoms; Oxygen: O, 2 atoms; Water: H2O, 4 H atoms and 2 O atoms (per molecule, but 2 H2O molecules for balance: 8 H, 4 O)

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

NGSS.MS-PS1-1

The elements and number of atoms represented on both sides of the equation support the law of conservation of mass because:

• the total number of each type of atom is the same on both sides of the equation.

• the equation shows more atoms on the product side than the reactant side.

• the equation allows atoms to be created or destroyed during the reaction.

• the types of elements can change during the reaction.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

A student mixes two solutions, which react to form the solid precipitate AgCl. The balanced chemical equation below shows the masses in grams of some of the reactants and products. AgNO3 + NaCl → AgCl + NaNO3 170 g + ? → 143 g + 85 g How many grams of NaCl were used in the reaction?

• 228 grams

• 58 grams

• 27 grams

• 125 grams

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Multipart - This question has two parts. A student mixes two solutions, which react to form the solid precipitate AgCl. The balanced chemical equation below shows the masses in grams of some of the reactants and products. AgNO3 + NaCl → AgCl + NaNO3 170 g + ? → 143 g + 85 g Part B Which statement supports the answer to Part A?

• The mass of the reactants is greater than the mass of the products.

• The mass of the products is greater than the mass of the reactants.

• The mass of the reactants is equal to the mass of the products.

• The mass of the products in a chemical reaction is doubled.

Tags

NGSS.MS-PS1-5

Which spot represents a subscript?

Tags

NGSS.MS-PS1-5

Match the correct part of the chemical equation with its descriptor.

• Reactants

• E

• Products

• B

• Subscript

• A

• Coefficient

• C

• Yields

• D

Tags

SPS3b

In a chemical equation the products are on the right side of the arrow. Are the products the beginning substances or the ending substances?

• beginning

• ending

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

The red numbers in the image below represent ________

• solvents

• coefficients

• subscripts

• elements

Tags

NGSS.HS-PS1-7