#14 - Endo/Exo, Scientific Notation, Enthalpy, & Q=mCΔT

Categorize these properties of endothermic and exothermic reactions:

Groups:

(a) Endothermic

,

(b) Exothermic

• heat energy is a product

• produces energy

• surroundings loses energy

• system gains energy

• surroundings feel warmer

• releases energy

• heat energy is a reactant

• needs energy

• reactants have more energy than the products

• absorbs energy

• reactants have less energy than the products

• surroundings feel colder

• system loses energy

• surroundings gain energy

Tags

NGSS.HS-PS1-4

Temperature is a measurement of the ​​ (a)   of the molecules inside a substance.

The ​ (b)   a substance is, the ​ (c)   the particles move, and the greater the ​kinetic energy.

The ​ (d)   a substance is, the ​ (e)   the particles move, and the lower the kinetic energy.

• colder
• less
• hotter
• more
• kinetic energy
• potential energy

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-2

Match the number in standard form to it's equality in scientific notation:

• 2.5 x 10^-1

• 250

• 2.5 x 10²

• 0.025

• 2.5 x 10¹

• 0.0025

• 2.5 x 10^-2

• 0.25

• 2.5 x 10^-3

• 25

If you use 12 g of water in a reaction that releases 1250 J of energy, what is the ΔT?

Q = ​ (a)  

m = ​ (b)  

C = ​ (c)  

ΔT = ​ (d)  

• 1250
• 12
• 4.18
• 24.9
• -1250
• 0.04
• -24.9

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-1

If you use 5 g of water in a reaction that has an initial temperature of 22.4°C and a final temperature of 45.8°C, how much energy was absorbed?

Q = ​ ​ (a)  

m = ​ (b)  

C = ​ (c)  

ΔT = ​ (d)  

• 5
• 4.18
• 23.4
• 489.1
• -489.1
• 27.9
• -23.4

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-1

If a reaction releases 57,000 J of energy and has an initial temperature of 22.4°C and a final temperature of 5.8°C, what was the mass of the water?

Q = ​ ​​ (a)  

m = ​ ​ (b)  

C = ​ (c)  

ΔT = ​​ (d)  

• 4.18
• 16.6
• 57,000
• 821.5
• -57,000
• -16.6
• -821.5

Tags

NGSS.HS-PS3-4

If a reaction has a mass of 13 g, absorbs 1,500 J of energy, has an initial temperature of 22.4°C, and a final temperature of 34.7°C, what is the specific heat capacity of the substance?

Q = ​ ​​ (a)  

m = ​ ​ (b)  

C = ​ (c)  

ΔT = ​​​ (d)  

• 9.38
• -1,500
• -12.3
• 13
• 1,500
• 0.11
• 12.3
• 4.18

Tags

NGSS.HS-PS3-4

Label the chemical equations and graphs correctly:

a

b

c

d

endothermic graph

endothermic equation

exothermic graph

exothermic equation

Tags

NGSS.HS-PS1-4

Calculate the enthalpy of both graphs:

a

c

20 - 40 = -20

160 - 80 = 80

40 - 20 = 20

80 - 160 = -80

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

When the change in enthalpy (ΔH) is positive, the reaction is ​​ (a)   . When the change in enthalpy (ΔH) is negative, the reaction is ​​ (b)   . In an exothermic reaction, energy moves from ​the ​ (c)   to the ​ (d)   . A chemical reaction that ​ (e)   heat is called an ​endothermic reaction.

• endothermic
• exothermic
• system
• surroundings
• absorbs
• releases

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1