CHM 2032 LAB MIDTERM (5 Labs)

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5 Rules of Lab Safety

1. recognize hazard 2. know protection 3. use protection 4. know the response 5. apply the response in time

Express number in proper exponential notation. 104,544

1.04544 x 10^5 0.00003456 3.456 x 10^-5 567,345,956 5.67345956 x 10^8

How many cm from the top of chromatography paper,should you stop the process?

1.5 cm

1 kg = ? grams

1000 grams

how do you find the mass of water in kg

1000 mL= 1 kg

Calculate the slope if rise is 6 and run is 1.5

4

proteins and carbs good energy

4.0 Cal/g

Solve and express your answer in proper exponential notation. (4.63 X 10^6) - (5.6 X 10^4)

4.574000 x 10^6

How many significant figures? 8.1035 X 10^33

5

Express number in proper exponential notation. 567,345,956

5.67345956 x 10^8

sig figs in 1010.00

6

Chromatography

A technique that is used to separate the components of a mixture based on the tendency of each component to travel or be drawn across the surface of another material.

graph

Diagram that represents the variation of one system factor in relation to the resulting variation of one or more other factors.

when dividing exponential numbers...

subtract the powers

extrapolation

projection; conjecture; stretch

specific gravity

ratio of a mineral's weight compared with the weight of an equal volume of water

Rf

ratio of distance traveled by component/ distance traveled by solvent front

Density is..........? (definition)

ratio of mass to its volume

specific gravity

ratio of the density of a substance to the density of a reference substance

combustion reaction

reaction with O2 (a reaction of peanut oil with oxygen; digestion)

If there is an accident, what should you do to be helpful and correct the problem?

recognize the hazard

Use when needed and know location of safety shower,fire blanket,first aid and shut off valves

safety equipment

exponential term

second factor in exponential notation (10)

When stapling the chromatography paper, edges

should not overlap

In case of a fire do this......

smother with a towel

exponent

specific whole number power (^x)

When adding/subtracting exponential numbers...

they need the same power. If they do not match, you must convert

inexact numbers

those whose values have some uncertainty

what is always an independent variable?

time

Calculate the amount of energy released per gram of peanut burnt, given 8 Cal of released energy and 0.5g of peanut to start with.

total amount of energy released/mass of peanut burned 8/0.5=16 Cal g

Triglycerides

triester produced by the reaction of glycerol with three fatty acids (peanut oily)

Miscible

Describes two liquids that are soluble in each other (Rubbing alcohol dissolves in grain alcohol)

broken glass

goes in designated conatiner

safety apparel

goggles, aprons, gloves

Express number in proper exponential notation. 0.00003456

3.456 x 10^-5

less dense

...... will float on top of the more dense

Round off number to 3 significant figures. 0.0256759

0.0257

Calculate the mass, in kg of water present in the calorimeter, using Equation 6, if you have 200mL of water.

0.20 kg (mass, kg= density * volume (L)) density = 1.0 200 mL times 1L/1000mL=0.20kg

Calculate the mass of burnt peanut if starting weight is 0.965g and 0.0134g after burning.

0.9516g (INITIAL WEIGHT - AFTER BURNING)

Select all correct answers. 1. Do not bump other students 2. No Roaming 3.Immediately report any accident,injury or incorrect procedure. 4.If you have an idea of an experiment, try it out.

1,2,3

Complete the following calculation and express using proper significant figures. B. 5.344 + 0.7345 + 12.9 + 0.0345

19.0

1cm^3=

1mL pure water

Complete the following calculation and express using proper significant figures. A. 8.434/4

2

Solve and express your answer in proper exponential notation. (3.40 X 10^-6/6.34 X 10^4) + (2.00 X10^-4)

2.000000536 x 10^-4

Round off number to 3 significant figures. 264.45

264

How many significant figures? 20400

3

Solve and express your answer in proper exponential notation. (4.6 X10^-5)+ (3 X10^-3)

3.046 x 10^-3

fat's food energy

9.0 Cal/g

exothermic reaction

A reaction that produces heat i.e. burning peanut

Density equation

D=m/v

significant figures rules

Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant.

exact numbers

Numbers that have no uncertainty and thus do not limit the number of significant figures in any calculation.

Why keep the beaker with solvent covered?

Prevent evaporation

stationary phase

The phase that does not move in chromatography. (liquid or solid)

ordinate

The y-axis is called the _______.

Why is it important to mark origin and solvent front?

This is needed to calculate the Rf

line graph

Used to compare the values of 2 variables.

What is the correct order to record mass of a liquid into a graduated cylinder?

Weigh the empty cylinder, add liquid, reweigh cylinder

Immiscible

liquids that are not soluble in each other (oil and water)

origin of chromatography

location of the spotted area

specific heat capacity of water

_______ is 1.0 cal per g per degree Celsius

Calorimeter

a measuring instrument that determines quantities energy released

The x-axis is call the _________.

abscissa

when multiplying exponential numbers...

add the powers

amount of energy released per gram

amount of energy released / mass of the peanut

paper chromatography

apply/spot a sample of the mixture we wish to separate near the bottom of the paper

Use only

authorized material and equipment

Contact Lenses can be worn in the lab anytime there is chemical use that may infuse under the lens?

can NOT be worn in the lab anytime there is chemical use that may infuse under the lens

soluble

capable of being dissolved (sugar in water)

specific gravity equation

density of substance/density of water

characteristic

digits to the left of the decimal

mantissa

digits to the right of the decimal

Rf (retention/retardation factor) formula

distance traveled by component(cm)/distance traveled by solvent front(cm)

safety is

everyone's responsibility

exponential notation

expresses numbers as the product of two factors

there are makeup labs

false

Digit term

first factor in exponential notation (x)

PHYSIOLOGIC ENERGY equals

food energy

Choose all that are not allowed in the lab?

food,drink, personal belongings, touching chemicals with hands

how do you find mass of peanut

initial mass - post mass

cannot be dissolved (Plastic soda bottle floats on a pond)

insoluble

when decimal place is moved to the right in exponential notation...

it is negative

when decimal place is moved to the left in exponential notation...

it is positive

you lose points when...

late for class

adding and subtracting sig figs

least number of decimal places

multiplying and dividing sig figs

least number of sig figs

slope formula

m=y2-y1/x2-x1 OR RISE/RUN

how do you find the amount of energy released from the burning peanut

mass of H2O x change in T x specific heat of water (which is 1.00)

Calculate the amount of energy released in Cal from the burning peanut given mass of 0.4kg of heated water, 16 degree Celsius water temperature increase.

mass times temperature change time specific heat of water (1.0) 16 times 0.4 times 1 = 6.4 Cal

What causes the rate of mixture to move apart(seperate from one another) during chromatography?

molecular structure differences

graphing calculators are

not allowed on the final

Iodine is

not safe to touch with hands

fatty acids

organic acids with long,unbranched chains of twelve or more carbon atoms

What will be used as the stationary phase

paper

______ is 9,0 Cal per gram

physiological energy for lipids

Energy definition

the ability to do work

solvent front

the furthest point reached by the solvent/leading edge of the mobile phase

Thomas seng is

the instructor

food produces...

the same amount of energy

significant sig figs in logs/antilogs

the sig figs to the right of the decimal (mantissa) are equal to the total amount of sig figs in the original number

What will be used as the mobile phase?

water/salt

mobile phase of chromatography

where the molecules can move, always a liquid or gas

Review safety

with your instructor before beginning

Using this slope of 10, if y-intercept is +45, write the equation for the line

y= 10x+45

What is the general equation of a line graph?

y=mx+b

in chromatography you need...

you need dry samples


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