TEAS CHEM

Extensive property

a property that depends on the amount of substance in a sample

Intensive property

a property that does not depend on the amount of substance in a sample

elasticity: physical or chemical property?

physical property of matter

volume: physical or chemical property?

physical property of matter

mass: physical or chemical property?

physical property of matter

color: physical or chemical property?

physical property of matter

Weight definition

is a measure of the force that gravity exerts on an object.

Mass definition

is a measure of the amount of substance within an object.

Volume definition

is a measure of the amount of space an object occupies.

Temperature

is a measure of how fast molecules are moving in a substance

Heat

is a measure of energy transfer - it's the amount of energy transferred from one substance to another.

Density

is the measure of the amount of mass per unit of volume.

(ratio between mass and volume of substance) ex: m/v

density

Melting Point

is the temperature and pressure at which a solid turns into a liquid

Boiling Point

is the temperature and pressure at which a liquid turns into a gas

Specific Heat Capacity

is the amount of heat needed to change the temperature of a unit mass of a substance by a certain unit of temperature.

intensive property examples

density, temperature, melting point, malleability, boiling point, specific heat capacity, and luster.

density, Intensive or Extensive

intensive

temperature, Intensive or Extensive

intensive

malleability - intensive or extensive

intensive

boiling point intensive or extensive

intensive

specific heat capacity intensive or extensive

intensive

Luster (intensive or extensive)

intensive

length (intensive or extensive)

extensive

mass (intensive or extensive)

extensive

heat intensive or extensive

extensive (If you double the amount of water in a pot, you'll need twice as much heat to raise the temperature by the same amount)

volume intensive or extensive

extensive

Density Formula

D=m/v

Relative Density formula

mass of any volume of a substance/ mass of an equal volume of water

Volume formula for Cube

V= a³

Volume formula for Rectangular Prism

a x b x c

Volume formula for Cylinder

V = πr²h

Volume formula for Sphere

V=4/3πr³

Volume formula for Cone

V = 1/3πr²h

Volume formula for Triangular Pyramid

V=a² x H/3

Volume displacement Formula

v=Vf-Vi

Conversion formula for cm^3 to m^3 (using 1000cm^3)

1000cm³x(1m/100cm³)=0.001m³

Weight Formula and Unit of Measurement

W=mg Newton

ex: box is 10kg, gravity on planet earth is 9.8m/s²

(10kg)x(9.8m/s²)= 98N

Heat capacity Measurement

J/K or J/C°

Which has a higher heat capacity Wooden handle or Iron Handle

an iron handle heats up more rapidly than a wooden one, which means iron has a lower heat capacity than wood, so it will require less heat for its temperature to rise.

Specific Heat Capacity Measurement

J/kg°C or J/kgK

Measurement for Energy

Joules (J)

equation that relates the heat energy to the specific heat capacity

Define each Variable

Q=mCΔT

Q=heat energy (in J)

M=the mass of the substance

C=the specific heat capacity of the substance

ΔT=the change in the substance's temperature.

A student must use 225 mL of hot water in a lab procedure. Calculate the amount of heat required to raise the temperature of 225 mL of water from 20.0 /C to 100.0 /C.

• q= heat (in joules, J)

• m = mass of the water (in grams, g)

• c = specific heat capacity of water = 4.18 J/g·°C

• ΔT = change in temperature (°C)

Step 1: Convert volume to mass

Since the density of water is approximately 1.00 g/mL, 225 mL of water has a mass of:

m=225mL×1.00g/mL​=225g

Step 2: Calculate temperature change:

100-20= 80

Step 3: Plug values into the formula

Q(?)= 225g x 4.18 × 80 = 75240 J or 75.2 kJ

75.2 kJ (Divide by 1000 to convert J to kJ)

Calculate the specific heat capacity of a new alloy if a 15.4 g sample absorbs 393 J when it is heated from 0.0/C to 37.6 /C.

c = 0.679 J/g C/C

Calculate the specific heat capacity of titanium if a 43.56 g sample absorbs 0.476 kJ as its temperature changes from 20.13/C to 41.06/C.

(0.522 J/g C/C)

kJ to J conversion

kJ x 1000=J

A 175 g piece of iron and a 175 g piece of aluminum are placed in a hot water bath so that they are warmed to 99.7/C. The metal samples are removed and cooled to 21.5/C. Which sample undergoes the greater heat change?

Iron:0.450 J/g·°C

Aluminum: 0.897 J/g·°C

(Al; -12.3 kJ Fe; - 6.08 kJ)

specific heat capacity equation

C=Q/mΔT

The burning of a sample of propane generated 104.6 kJ of heat. All of this heat was use to heat 500.0 g of water that had an initial temperature of 20.0/C. What was the final temperature of the water?

water heat cap: 4.18 J/g°C

Step 1: Convert heat from kJ to J

q=104.6kJ = 104600J

Step 2: Plug known values into the formula

104600=500.0⋅4.18⋅(T_final​−20.0)

Step 3: Solve for T_final​

104600=2090⋅(T_final​−20.0)

50.05≈ T_final​−20.0

T_final​−70.0∘C

(70.0/C)

If 700 g of an unknown metal requires 6.30 kJ of heat to raise its temperature by 10.0 °C, what is the metal's specific heat capacity in J/kg°C?

Step 1: Convert quantities

q=6.30kJ=6300J

m=700g=0.700kg (The question asked for heat capacity in J/kg °C) So you have to convert to kg

Temperature change:
ΔT=10.0∘C “raise its Temp by 10 degrees” is heat change already.

Step 2: Solve for specific heat capacity c

6300=0.700⋅c⋅10.0

6300=7.0⋅c

c=6300/7.0 ​= 900J/kg°C

900J/kg∘C

Steps when calculating a SHC, Ti or Tf, Heat, or heat change Problem

1. Identify whats being asked SHC, Tf, or HC

2. Figure out the equation for whats being asked

3. Plug in all varibles with units attached to sway confusion

4. Solve

5. Ensure the unit aligns with the question being asked

If 500 g of iron is at a temperature of 20.0 °C, how much heat will be required to raise its temperature to 45.0 °C if the specific heat capacity of iron is 475 J/kg°C?

Step 1: Convert g to kg because heat cap is in kg

500g = .500kg

Step 2: calculate heat capacity, V_f - V_i, 45-20= 25

Step 3: Plug in and solve

q= 0.500 ⋅ 475 ⋅ 25.0= 5937.5J

Q=5937.5J

Conduction definition

a process by which heat is transferred by direct contact between two bodies

Heat energy definition

the energy of movement of the particles of a substance

Thermal equilibrium Definition

a condition in which there is no net flow of heat between two bodies

Zeroth law of thermodynamics definition

if two thermodynamic systems are both in thermal equilibrium with a third system, then the two systems are in thermal equilibrium (if A=B and B=C, the A=C)

Conduction Example

the transfer of heat from the bottom of a hot pan to the food that is being cooked.

smallest unit of matter

atom

the center of the atom, which is made up of protons and neutrons

nucleus

a positively charged subatomic particle

proton

the number of gives an atom its identity; it is located in the nucleus at the center of an atom

protons

a neutrally charged subatomic particle

neutron

a negatively charged subatomic particle that moves around the outside of the nucleus of an atom along circular paths called orbitals

electron

the area around the nucleus of an atom that contains electrons traveling around the nucleus

Electron Cloud

imaginary paths surrounding the nucleus of an atom along which electrons travel

Orbitals

Left side of periodic table

metals (except hydrogen)

rows(horizontal) on the periodic table

periods

Columns(vertical) on the periodic table are called:

families

Center of the periodic table

transition metals

Right side of periodic Table

non-metals

valence electrons on periodic table

group number

The number in the tens place of the group number indicates

The number of outer electrons (Valence Electrons)

Fluorine's number of outer electrons (group #17)

7

octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

Atomic Number

the number of protons in the nucleus of an atom

Atomic Mass

the number of protons plus neutrons in the nucleus of an atom.

Atomic Weight

the average weight of all a particular element's isotopes.

the average weight of all a particular element's isotopes.

Atomic Weight

the number of protons plus neutrons in the nucleus of an atom.

Atomic Mass

the number of protons in the nucleus of an atom

Atomic Number

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

22

22

4

22

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

25

25

7

25

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

5

5

3

5

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

32

32

4

32

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

33

33

5

33

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

47

47

1

47

what do Valence Electrons Determine?

The chemical reactivity and bonding behavior of an atom, influencing how it interacts with other elements.

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

27

27

9

27

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

3

3

1

3

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

19

19

1

19

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

57

57

3 ( in group 3)

57

How many Protons in Nucleus?

How many Electrons?

How many Valence Electrons?

Atomic Number?

37

37

1

37

What is an isotope?  and what is its result

An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons, resulting in a different atomic mass.

Name

#of neutrons in the isotope

Rb-87

Rubidium

50

13 more neutrons than a normal atom of Rubidium

Name

#of neutrons in the isotope

Zr-60

Zirconium

60-40=20 neutrons

Name

#of neutrons in the isotope

Pt-106

Platnium

106-78=28 neutrons

Name

#of neutrons in the isotope

Co- 93

Cobalt

93-27=66 neutrons