chem lab exam

Evaporating dish

used to evaporate a solution

crucible & cover

used to heat small samples to high temperatures

crucible tongs

used to pick up a crucible

watch glass

used to cover a beaker or to hold a small amount of a substance

stirring rod

stirring rod used to mix or combine two or more substances in a test tube or a beaker

forceps

used to pick up a small objects or one that is hot

pinch clamp

used to close rubber tubing

spatula

used to transfer small amounts of a solid

buchner funnel

used to separate solids from liquids using a vacuum

thermometer

used to measure the temperature of a substance

pipet

used to transfer a specific volume of liquid solution to a container

buret

used to deliver a measured amount of solution with a known concentration

medicine dropper

used to deliver drops of a solution or liquid

beaker, erlenmeyer flask, Florence flask

used to hold solids or liquids and carry our reactions

graduated cylinder

used to measure out accurate volumes of liquid

wide-mouth bottle

used to contain a gas or for reactions

funnel

used to transfer liquids to another container and when filtering out solids

shell vial

used to hold small amounts of solid substances

bunsen burner

used to provide heat

ring support stand with clay triangle

used to support triangle or wire gauze during the heating process

test tube

a small container for solutions and reactions

test tube brush

used to clean a test tube

wired gauze

used to support a beaker on an iron ring during heating

test tube holder

used to hold a test tube during heating or while still hot

how do you know if an object will sink or float

lighter object will float heavier object will sink

Why does a sodium street lamp give off a yellow color while a neon light gives off a red color?

because the electron are arranged differently

what is the flame color for Ca

orange-red

what is the flame color of K

pink

what is the flame color of Ba

yellow

what is the flame color of Sr

red

what is the flame color of Cu

green

what is the flame color of Na

orange

the four parameters used to describe a gas are

P,V,n,T

the two variables that are being tested in Boyles law are

pressure and volume

What two variables are being tested in Gay Lussac’s Law

temperature and gas

the relationship between pressure and volume of a gas is

inversely proportional

the relationship between temperature and pressure of a gas is

directly proportional

what is included in a chemical equation

products, reactants, yield

how does a combination reaction differ from a decomposition reaction

combination reactions use simple compounds to create a complex product. a decomposition reaction splits the substance into simpler substances

what kind of reaction is this 2Al + Fe2O3 → Al2O3 + 2Fe

single replacement

what kind of reaction is this 2KClO → 2KCl + 3O2

decomposition

what kind of reaction is this 2Li + Cl2 → 2LiCl

combination

what kind of reaction is this C2H4 + 3O2 → 2CO2 + 2H2O

Combustion

what kind of reaction is this 2CrCl3 + 3H2S → Cr2S3 + 6HCL

double replacement

what is evidence of a chemical change

bubbles, precipitation, color change, heat production or absorption

what does the + mean in a chemical reaction

separates two or more formulas

what does the → mean in a chemical reaction

reacts to form products

what does the →(triangle on top of arrow) mean in a chemical reaction

reactants are heated

what does the (s) mean in a chemical reaction

solid

what does the (l) mean in a chemical reaction

liquid

what does the (g) mean in a chemical reaction

gas

what does the (aq) mean in a chemical reaction

aqueous

a pH of 2.0 is acidic or basic?

acidic

a pH of 11.0 acidic or basic

basic

what is a buffer

maintains the pH of a solution by reacting and neutralizing any acid or base added

what is the symbol for an alpha particle

4 2 He

what is the symbol for a beta particle

0 -1 e

what is the symbol for a positron

0 1 e

what is the symbol for a gamma particle

0 0 y

radiation originates from where in a cell

nucleus

what were the substances tested in the nuclear chemistry experiment

coffee, seaweed, potassium iodide, Sr-90,CO-60

the substance that was the most radioactive in the nuclear chemistry experiment was

Sr-90

the substance that was the least radioactive in the nuclear chemistry experiment was

coffee

to shield alpha rays you can use

skin

to shield beta rays you need

lab coat/ clothes

to shield gamma rays you need

lead/concrete

what is the functional group of alkyl halides

carbon halogen bond

what is the functional group of alcohols

-OH

what is the functional group of ethers

-O-t

what is the functional group of aromatics

benzene ring with a circle in the middle

what is the functional group of carboxylic acids

O || -C-OH

what is the functional group of aldehydes

O || -C-H

what is the functional group of ketones

O || -C-

what does the chromic acid test for

wether or not an alcohol will oxidize

what does a positive test result look like in the chromatic acid test

chromatic acid solution going from orange to green

what alcohol reacts with chromatic acid

ethanol, 2-propanol , cyclohexanol, phenol

what alcohol doesn’t oxidize in chromatic acid

2-methyl-2-propanol

what the iron chloride test test for?

wether or not something is a phenol

what is a positive result in the iron chloride test?

color change from yellow to purple

what are the functional groups in aspirin

carboxylic acid, aromatic, ester

what are the functional group in salicylic acid

hydroxyl group and carboxylic acid

formula for percent yield

actual / theoritical (100)

what does the Benedicts test test for

reducing sugars

what does a positive result in a Benedicts test look like?

green/yellow if low , red if high

what does a negative result in a Benedicts test look like?

blue (no color change)

what does the Seliwanoff test test for

Ketoses

what does a positive result in Seliwanoffs test look like?

dark red coloring means a ketose

what does a negative result in Seliwanoffs test look like?

light pink coloring means an aldose

what does the fermentation test test for

wether or not a carbohydrate can be utilized

what does a positive result in a fermentation test look like?

bubbles

what does a negative result in a fermentation test look like?

no bubbles

what does the iodine test test for?

the presence of carbohydrates in starch

what does a positive result in an iodine test look like?

a violet or black color

what does a negative result in an iodine test look like?

a red color

what are the different classes of lipids

triacylglycerols, glycerophospholipids, sphingolipids, steroids

what does the bromine test of lipids test for?

wether a fatty acid is saturated or unsaturated

what is a positive lipid bromine test look like

color fading (unsaturated)

what is a negative lipid bromine test look like

color stays ( saturated )

what is the Rf formula of a chromatogram

Rf\= distance traveled/distance traveled by solvent

what are the functional groups of an amino acid

amine and carboxylic acid