Midterm chem lab review
How many significant figures?
1 significant figure because both zeros appear to the LEFT of the non-zero digits.
Precipitation
A __________ reaction occurs in which dissolved substances react to form an insoluble salt
SYNTHESIS.
A combination reaction is also known as ____________.
One
A decomposition reaction breaks down how many reactant compounds into multiple products?
Polyatomic ion
A group of atoms that has a charge
32.9 ± 0.3 mL
A series of measurements In the lab led to an experimental result of 32.9 ml, with a calculated standard deviation of 0.3 mL. What is the standard way to report this result?
Precise
A set of measurements is ___________ if all Measurements are reasonably close to one another .
Decomposition reaction
AB --> A + B
True
All diatomic elements are NON-metals. True or false
Gases (except for bromine)
All diatomic elements are ________ at room temperature.
NH₄Cl
Ammonium chloride compound name
measured
Any number that uses a measuring tool to determine a quantity (rulers, balances, measuring cups, graduated cylinders)
0.2964
Calculate the moles of ammonia present in a 5.047 g sample of the molar mass of ammonia is 17.030 g/mol.
Opposite
Combination (synthesis) and decomposition reactions are ________________ processes.
General spill kit
Determine wether a specialized or generalized spill kit is needed for this chemical : phosphoric acid
CuO, a black solid
Heating copper hydroxide ( Cu(OH)₂ produces ?
3
How Many significant figures : 14.8 m
Evaporation
How can a solid dissolved in water be separated from the water?
Estimate one digit past the smallest precisely known digit or marking
How do you determine the last digit in any measured number ?
Hold down ⬇️ the plunger
How do you hold the plunger of a pipette when dispensing a liquid?
4 sig figs - bc all the zeros are significant because they appear to the right of the non-zero digit and there is a decimal point present.
How many significant figures in 1.000 g/mL
2 ; zeros aren't significant because they appear to the right of non zero digit but there IS NO DECIMAL POINT PRESENT.
How many significant figures in 6200
2
How many significant figures? 0.0034
4
How many significant figures? 0.01060
4
How many significant figures? 5.060
Hydrogen gas
H₂
Air inlet
Identify
Gas cock
Identify
Gas inlet
Identify C.
Has a flash point below room temp
Identify the description of this nfpa diamond
Stable, has health risks but no special hazards
Identify the description of this nfpa diamond
Gas regulator
Identify the part
A
Identify which diamond says "moderately stable or reactive "
It will decrease by half
If you double the wavelength of light , what happens to the energy of the photons?
Lavender
In a flame test, what color does potassium (k) produce?
Estimated digit
In all measurements, the last significant digit , wether a zero or not, is the _________________.
Dry, dark, and cool
In general, which characteristics are needed for a location to be suitable for chemical storage ?
Accepted value
In the percent error equation, the "error" is the difference between the experimental value and the ___________value .
The magnesium metal is gone , gas bubbles are. I longer produced
In the reaction of magnesium metal with hydrochloric acid , how do you determine when the magnesium metal has reacted completely?
Burette
It is an extremely accurate device with a stopcock at the bottom used to measure volumes of reagents .
Lit with a Bunsen burner
Magnesium reacts with oxygen in the air when _________________. Unlike other reactions , you should not look directly at this reaction.
Mass of the mixture of components
Mass is conserved in an exotic the sum of the individual masses equals the _________.
Ionic
Metal and a nonmetal
Impurities
Minor components in a mixture are called _______________.
Mixtures
Most of the matter people encounter in everyday life consist of ___________ of different substances.
Sodium hydroxide
NaOH
Mercury and hydrofluoric acid
Name two substances that require specialized clean up procedures if they are spilled.
Accuracy
Note that a set of measurements can have good precision , or values that are close to one another, but be far away from an ___________ value . (Accuracy)
GIVE
Oxidizing agents ___________ oxygen to another substance.
Exothermic (reaction accompanied by release of heat), warm to touch, evolution of brown gas
Reaction of copper wire and nitric acid
REMOVE
Reducing agents _____________ oxygen from another substance.
Precision
Refers to the closeness among a SET of measurements
Accuracy
Refers to the closeness between a measurement and it's Accepted value
Student A bc that students data has a smaller deviation
Suppose 2 students perform a titration experiment multiple times , resulting in the average concentrations reported here .which has the more precise work?
Open the air inlet further.
Suppose you light a Bunsen burner and notice that the flame is very yellow and too short . To get a blue flame, you :
Atomic number / number of protons
The bottom left number in isotope notation represents the ______________.
Variable
The composition of a hetergenous mixture is _____________.
Homogenous
The composition of this mixture is uniform.
Diatomic elements
The elements ending in "-gen" including halogens form __________ molecules.
Solubility
The extent to which a substance may be dissolved in water or any other solvent
Empirical formula
The most reduced ratio of elements in a compound.
Precipitation
The process of an insoluble salt forming from aqueous ions and falling out of solutions.
Physical
The separation of components of a mixture is based upon the fact that each component has different _____________ properties.
Distillation
The separation of liquids based on their boiling points.
Mass number
The top number on isotope notation represents ________________.
Elements molar mass
To calculate an empirical formula, start by converting the mass of each element to moles using each _________________.
Left
To identify a combustion reaction, O2 needs to be a reactant on the _________ side of the reaction arrow.
Open gas regulator further
To increase the size of a flame of Bunsen burner, you:
Molecular formulas
Unlike _____________ formulas, empirical formulas do not provide information about the absolute number of atoms in a single molecule of a compound.
Clay triangle
Used to hold a crucible while it is being heated
Components
What are the substances making up a mixture called?
Have No Fear Of Ice Cold Beer
What is the acronym for diatomic elements?
Converting the mass of each element to moles
What is the first step when calculating an empirical formula ?
Red
What is the longest visible wavelength? ( shortest is violet)
Extraction
What process is used to separate soluble compounds from insoluble compounds?
NaOH (sodium hydroxide)
What was added to the nitric acid after the copper wire dissolved to make it turn blue?
Blue with no gap between burner and flame
When a Bunsen burner is properly adjusted , what should the flame look like ?
Closing parentheses for any open parentheses An equal sign at the beginning of the formula
When inputting a formula into excel or other spreadsheet software, what components are required for the formula to function properly?
Nalgene bottle with cap
Where to dispose titrant solution
Pure
Whereas __________ substances have fixed compositions, the composition of mixtures can vary.
Group 1 elements
Which elements react most vigorously with water?
Transition metals
Which group of elements need a Roman number assigned to them ( after the metal) the numeral denotes the charge and the oxidation state
Liquid
Which phase is not present in sublimation.
Combustion reaction
Which reaction requires O₂ as one reactant?
Insoluble
Which substances readily precipitate from a solution?
Hazard signs ( flammable, oxidizer, corrosive) , NFPA diamond , gas cylinder signs
Which types of signs are posted to convey information about chemical storage?
Limiting reactant
a reactant that is totally consumed when the chemical reaction is completed.
Ions
an atom that has gained or lost electrons, so now has more of fewer electrons than it does protons
Isotopes
atoms that have the same number of protons but different numbers of neutrons
2 nonmetals
covalent ( molecular) compounds are made of
NaCl
sodium chloride (salt)