Balancing Chemical Equations and State Symbols

Why is it necessary to balance chemical equations?

• To use fewer chemicals in reactions

• To make equations look simpler

• To comply with the conservation of atoms

• To ensure energy conservation

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

What is the role of coefficients in a chemical equation?

• They indicate the temperature at which a reaction occurs

• They represent the volume of reactants used

• They adjust the number of molecules of reactants and products

• They determine the speed of the reaction

In the combustion of methane, what are the products?

• Hydrogen Peroxide and Carbon

• Carbon Dioxide and Water

• Carbon Monoxide and Hydrogen

• Methane and Oxygen

Tags

NGSS.MS-PS1-5

What does a diatomic gas refer to?

• A gas that exists at double the atmospheric pressure

• A gas that forms molecules consisting of two atoms

• A gas that is doubly reactive

• A gas used in double the quantity in reactions

Tags

NGSS.MS-PS1-1

How is the equation balanced when sodium reacts with chlorine gas?

• By using a catalyst

• By adding a coefficient of 2 in front of sodium and sodium chloride

• By reducing the amount of chlorine gas used

• By increasing the temperature

Tags

NGSS.MS-PS1-5

In the reaction of calcium carbonate with hydrochloric acid, what is added to balance the equation?

• A coefficient of 2 in front of HCl

• An increase in the amount of water produced

• A decrease in the amount of calcium carbonate

• A catalyst to speed up the reaction

Tags

NGSS.MS-PS1-5

What does it mean when a gas is described as 'diatomic' in a chemical equation?

• It forms molecules that consist of two identical atoms

• It is twice as dense as monatomic gases

• It consists of two different atoms

• It reacts twice as fast as other gases

Tags

NGSS.MS-PS1-1

What is the purpose of state symbols in chemical equations?

• To indicate the physical state of reactants and products

• To show the chemical properties of substances

• To display the color of the chemicals involved

• To represent the solubility of substances

Which state symbol is used for aqueous solutions?

• s

• l

• aq

• g

Tags

NGSS.MS-PS1-4

What does the subscript in state symbols indicate?

• The concentration of the solution

• The quantity of the substance used

• The physical state of the substance

• The reactivity of the substance

Tags

NGSS.MS-PS1-1