9C chemistry 2nd midterm review 1 | Baamboozle - Baamboozle

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If the sign of enthalpy change is NEGATIVE, the reaction is ___________.

exothermic

This is an energy profile diagram. Number(2) indicates the _______ _________ and number(3) indicates the _____ ________.

activation energy, enthalpy change

Why does breaking up solid reactants into smaller pieces increase the rate of reaction?

it increases the surface area of the reactants

What type of reaction is shown by the energy profile diagram?

exothermic reaction

In an exothermic reaction, the energy released on forming new bonds is _____________ than that needed to break the old bonds.

greater

Which reaction might have been performed: i) at a higher temperature with dilute reactants? ii)used the greatest amount of reactants? iii)used the dilute reactants?

i)B ii)A iii)C

The graph shows a reaction between magnesium and HCl solution in a beaker. Reactants are measured. Which curve is performed at a higher temperature?

curve B

To break bonds, energy is _____________. The process is _____________(exothermic/endothermic).

absorbed, endothermic

The heat energy change in chemical reactions is called ______________ change.

enthalpy

When the temperature is increased, the chemical reaction time is ___________.

shortened/decreased

Name 4 factors that affect the rate of reaction.

Temperature, concentration, pressure(gas), particle size/surface area, catalysts

If the sign of enthalpy change is NEGATIVE, the reaction is ___________.

exothermic

The minimum amount of energy required for a reaction to occur is called the __________ __________.

activation energy

A _____________ is a substance that changes the rate of a chemical reaction and is chemically unchanged at the end of the reaction.

catalyst

A reaction that absorbs energy from the surroundings is an ___________ reaction.

endothermic

Why do most reactions start fast and get slower and slower?

The concentration of reactant molecules gets less and less as reactants are converted to products.

For a reaction of X +Y -------> Z, which curve indicates the reactants and which curve shows the products?

Blue curve(products), red curve(reactants)

How does a catalyst increase the rate of a reaction?

by lowering the activation energy.