Chem Lab
⟶ Δ→ + (l)
-Substances on the reactants side are converted to the substances on the products side. -Heat is applied. -There are two separate substances on either the products side or the reactants side. -The substance is a liquid.
What is the value of the gas constant, R, in units of L⋅atm/mol⋅K? Report the value with at least three significant figures.
0.0821
Calculate the moles of ammonia present in a 1.769 g sample if the molar mass of ammonia is 17.030 g/mol.
0.1039 moles of substance=mass in g×1 mol of substance/molar mass
How many moles of H2 can be formed if a 3.24 g sample of Mg reacts with excess HCl?
0.133 mol H2 3.24 g Mg×1 mol Mg/24.3 g Mg×1 mol H2/1 mol Mg
Perform the calculation, rounding your answer to the proper number of significant figures. 0.32610 ÷ 1.830 =
0.1782
Suppose you are titrating vinegar, which is an acetic acid solution of unknown strength, with a sodium hydroxide solution according to the equation HC2H3O2+NaOH⟶H2O+NaC2H3O2 If you require 34.27 mL of 0.1077 M NaOH solution to titrate 10.0 mL of HC2H3O2 solution, what is the molar concentration of acetic acid in the vinegar?
0.3690 M -moles of NaOH=34.27 mL NaOH×1 L/1000 mL×0.1077 mol NaOH/1 L NaOH -moles of HC2H3O2=moles of NaOH×1 mol HC2H3O2/1 mol NaOH -concentration of HC2H3O2=moles of HC2H3O2/10.0 mL HC2H3O2×1000 mL/1 L
Select the coefficients necessary to balance each equation. Choose a coefficient for every compound. __NH4NO3⟶NHX4NOX3⟶__N2O+NX2O+__ H2O __Fe+Fe+__HCl⟶HCl⟶__FeCl3+FeClX3+__H2
1,1,2 2,6,2,3
Suppose you heat a metal object with a mass of 31.4 g to 96.0 oC and transfer it to a calorimeter containing 100.0 g of water at 18.1 oC. The water and metal reach a final temperature of 23.8 oC. What is the specific heat of the metal in J/g-oC?
1.1 q=mcΔT qwater=100.0 g×4.184 J/g-∘C×(23.8∘C−18.1∘C) qmetal=31.4 g×c×(23.8∘C−96.0∘C)=−qwater c=−qwater/31.4 g ×(23.8∘C−96.0∘C)
A graduated cylinder contains 10.00 mL water. A 14.74 g piece of aluminum is added to the water, and the volume rises to 15.46 mL. What is the density of the aluminum in g/mL?
2.7 d=m/V 15.46 mL - 10.00 mL = 5.46 mL
Perform the calculation, rounding your answer to the proper number of significant figures. 0.867 + 3.72 + 18.0045 =
22.59
Calculate the area of a rectangle in cm2 with a width of 8.5 cm and height of 2.9 cm. Be sure to include the proper number of significant figures.
25
Suppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 1.61 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 28.55 mL. What volume, in mL, of base was required for the titration?
26.94 mL
The temperature of a room is 22.5 °C. What is this temperature expressed in Kelvin (K)?
295.65 K 22.5∘C+273.15
Calculate the volume, in cubic centimeters, of a box which is 125 cm long, 37 cm wide, and 68 cm high. Report your answer with correct significant figures in cubic centimeters.
3.1x10^5 volume of the box=125 cm×37 cm×68 cm=310000 cm3
Perform the calculation, rounding your answer to the proper number of significant figures. 0.841 x 7.34 x 5.1 =
31
A 24.5 g sample of solution has a density of 0.768 g/mL. What is the sample volume (in mL)?
31.9 mL V=m/d
Refer to the periodic table to find the correct molar mass for each element and compound. O2 C2H6 O CH4 Cl S
31.998 g/mol 30.067 g/mol 15.999 g/mol 16.042 g/mol 35.446 g/mol 32.059 g/mol
What is the correct reading of the volume in the pictured buret? Make sure to report your reading with the appropriate significant figures.
39.95 mL
Suppose you are measuring the mass of a solid sample on a balance using a weigh boat. You record the data in a table. Mass of weigh boat 1.065 g Mass of weigh boat and sample 5.815 g What is the mass of the solid sample (in g)?
4.75 g Mass of weigh boat and sample−Mass of weigh boat=Mass of sample
Identify which balance was used to make each mass reading.
5.43 g A balance with ±0.01 g tolerance 4.0000 g A balance with ±0.0001 g tolerance 6.539 g A balance with ±0.001 g tolerance 0.90 g A balance with ±0.01 g tolerance 1.230 g A balance with ±0.001 g tolerance
A student removes a chemical sample from a reagent bottle to be used in an experiment. What should he do with any excess chemical remaining from this sample after the experiment is complete?
Check and see if anyone else can use the chemical. If not, discard in the proper waste container.
What are the best practices for safely handling waste in the lab?
Check labels or instructions before any disposal. Always wear appropriate Personal Protective Equipment.
Determine whether each observation generally corresponds to a physical change or a chemical change. A precipitate is formed from two solutions. Bubbles are produced upon mixing two solutions. The color of a substance changes over time. A solid dissolves into water. A liquid freezes into a solid. A solution heats up upon mixing with another.
Chemical change Chemical change Chemical change Physical change Physical change Chemical change
Identify the characteristics of a good recrystallization solvent.
Dissolves a chemical sample well at high temperatures. Does not dissolve a chemical sample well at low temperatures.
Determine each type of reaction. CaCl2(aq)+Na2CO3(aq)⟶2NaCl(aq)+CaCO3(s) 2C2H2(g)+5O2(g)⟶4CO2(g)+2H2O(l) NH4NO3(s)⟶N2O(g)+2H2O(l) 2Fe(s)+6HCl(aq)⟶2FeCl3(aq)+3H2(g) CO(g)+2H2(g)⟶CH3OH(l)
Double replacement Combustion Decomposition Single replacement Combination
How do you determine the last digit in any measured number?
Estimate one digit past the smallest precisely known digit or marking.
Match each element name to its correct symbol. Fluorine Sodium Silver Phosphorus Iron
F Na Ag P Fe
For each atom, determine how many dots should be drawn around the element symbol in the Lewis structure for a lone, neutral atom. The Lewis structure of an oxygen atom should have - dots drawn around the symbol O. The Lewis structure of a calcium atom should have - dots drawn around the symbol Ca. The Lewis structure of a nitrogen atom should have - dots drawn around the symbol N. The Lewis structure of an aluminum atom should have - dots drawn around the symbol Al. The Lewis structure of a fluorine atom should have - dots drawn around the symbol F.
6,2,5,3,7
Perform the calculation, rounding your answer to the proper number of significant figures. 6.16 - 0.00086 =
6.16
Knowing that one day is 24 hours and one hour is 60 minutes, how many minutes are in 4.7 days?
6768 minutes 4.7 days×24 hours/1 day×60 minutes/1 hour
The H2 produced in a chemical reaction is collected through water in a eudiometer. If the pressure in the eudiometer is 760.0 torr and the vapor pressure of water under the experimental conditions is 21.4 torr, what is the pressure (torr) of the H2 gas?
738.6 torr Ptotal=PH2O+PH2 760.0 torr−21.4 torr
Sulfuric acid, H2SO4, is an important industrial chemical, typically synthesized in a multi-step process. What is the percent yield if a batch of H2SO4 has a theoretical yield of 3.1 kg, and 2.8 kg are obtained at the end of the process?
90 percent yield=2.8/kg3.1 kg×100
What is the value of 222 calories in joules (J)?
928.8J 1 calorie=4.184 joules 222 cal×4.184 joules/1 cal
What information does not need to be included a chemical waste label?
A description of the experiment the chemicals were used for
Why should you use a finely ground solid when determining the melting point of a sample?
Air pockets in a coarse sample could disrupt heat distribution. Uniform, small particles heat more consistently throughout the sample.
Identify the necessary parts to build a calorimeter.
An exterior styrofoam cup An interior styrofoam cup Thermometer Cover
The indicator phenolphthalein is added to the _____________.
Analyte
When performing a melting point determination, how should you report your findings?
As a range from the temperature when melting starts to the temperature when it ends
What parts are present in every chemical equation?
At least one reactant At least one product An arrow
Using the letters on the image, identify each component of the Bunsen burner. A B C D
Barrel Air inlet Gas inlet Gas regulator
What is the best course of action if solid material remains in the flask after the heating step of a recrystallization?
Filter the hot mixture.
What is the advantage of fluted filter paper shown compared with cone-shaped filter paper?
Fluted filter paper has more surface area suitable for collecting solid.
Using the letters on the image, identify each component of the liquid waste set-up. A B C D
Funnel Primary container Waste label Secondary container
In the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely? Select all that apply. Mg(s)+2H+(aq) →Mg2+(aq)+H2(g)
Gas bubbles are no longer produced. The magnesium metal is gone.
Match each lab incident to the item of PPE that will protect you from it. Each item of PPE will only be used once. While picking up a buret, an unknown solution left by a previous solution drips onto your hand.____ While checking on a stirring solution, the solution splashes up towards your face.___ While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench.___- While pulling an empty beaker off the shelf at the beginning of the lab, it slips out of your hand onto the floor.+___
Gloves Goggles Lab coat Closed-toe shoes
Identify the types of information that are necessary to communicate with emergency responders.
How the incident happened, Any other hazards present in the lab, Any chemicals involved in an incident
A sample of gas is subject to changes in conditions. Predict the effect of each change. The pressure and the temperature are both decreased by 50%. What will happen to the volume?-- The pressure and volume are increased. What will happen to the temperature?--- The pressure is kept constant, while the temperature is decreased. What will happen to the volume?-- The volume and temperature remain constant, while some of the gas is let out of the container. What will happen to the pressure?--
It will stay the same. It will increase. It will decrease. It will decrease.
When taking a measurement with a pH meter, keep the instrument in the---until it is needed. Rinse the pH meter with---and gently pat dry. Place the meter in the sample solution, and record the measurement when the pH---
storage solution, deionized water, stabilizes
Given the pKa of each acid, determine whether it is strong or weak. sulfuric acid, pKa=-5--- nitric acid, pKa=-2-- citric acid, pKa=3.1-- acetic acid, pKa=4.7--
strong strong weak weak
In the context of a balanced chemical equation, a---is a number to the lower right of an element or ion within formula and it applies to---A===is a number to the left of a formula and it applies to---Only---should be added or changed when balancing chemical equations.
subscript only the part of the formula it follows. coefficient the entire formula it precedes. coefficients
Mass is conserved in an experiment if the---of the individual component masses equals the mass of the---
sum, mixture of the components.
The equivalence point of any acid-base titration can be determined visually from a titration curve by finding the place where
the curve has the steepest slope.
A titration curve is a plot of---on the x-axis and---on the y-axis.
titrant volume, pH
The pKa of an acid can be determined through--with a strong base. Gradually increase the volume of the base, stopping--the equivalence point is reached. The pKa of the acid is equal to the pH at the--midway volume to the equivalence point
titration, after, midway volume to the equivalence point.
Suppose an air bubble is trapped in the eudiometer before starting the experiment. After the experiment is finished, the resulting value of R would be
too large
To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the___of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the____of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from___
top, bottom, eye level.
Determine whether each of the properties described applies to volumetric or graduated glassware. Used for applications in which great accuracy is needed Capable of measuring a range of volumes of liquid Designed to measure one specific volume of liquid
volumetric, graduated, volumetric
Identify the aspects of the pictured graph that are missing or contain errors.
x-axis label, y-axis numeric range, Title
Suppose 0.0350 g Mg is reacted with 10.00 mL of 6 M HCl to produce aqueous magnesium chloride and hydrogen gas. Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g)
Magnesium metal
What practice will not help you make an accurate volume reading on a buret at the beginning of a titration?
Make sure that the meniscus starts exactly at 0.00 mL.
When taking pH measurements of solutions, why is it important to stir thoroughly after adding each reagent?
Mixing helps ensure that the measured pH is reflective of the entire solution.
What is the correct formula for manganese(II) fluoride?
MnF2
Hydrochloric acid and sodium hydroxide react to form _____________.
NaCl(aq) + H2O(l)
The reaction between sodium hydroxide and hydrochloric acid is considered which type?
Neutralization
Match each polyatomic ion formula to its name. NO2− SO42− SO32− ClO4− OH− ClO3−
Nitrite Sulfate Sulfite Perchlorate Hydroxide Chlorate
Determine whether or not each chemical formula is an empirical formula. C6H12O6 CaCO3 NaMnO4 Ba3(PO4)2 K2C2O4
Not an empirical formula Empirical formula Empirical formula Empirical formula Not an empirical formula
What is generally the best approach when liquid from a large reagent bottle is needed in an experiment?
Pour some of the reagent from the bottle into a beaker, then use as needed in the procedure.
Identify the common indicators that a chemical reaction has occurred.
Precipitate being formed A color change A change in temperature Bubbles being produced
Determine whether each melting point observation corresponds to a pure sample of a single compound or to an impure sample with multiple compounds. Experimental melting point is close to literature value Narrow melting point range Experimental melting point is below literature value Wide melting point range
Pure sample of a single compound Pure sample of a single compound Impure sample of multiple compounds Impure sample of multiple compounds
What is the first step for response to an emergency situation?
Remain calm and quiet, gather information, and assess the situation
Which formula is not an example of an ionic compound?
SO3
If crystal growth does not start on its own after the solution in the flask returns to room temperature, identify the best ways to promote this process.
Scratch the bottom of the flask gently with a stirring rod. Add a bit of solid as a seed crystal.
How should spill cleaning materials be discarded?
Seal in a labeled plastic bag, then place in the solid waste container.
What is the recommended order of measurements to report the most accurate melting point possible? Use slow heating to carefully observe melting. Use quick heating to estimate the melting point. Use slow heating to confirm the careful measurement.
Second step First step Third step
Determine what type of reaction each unbalanced chemical equation represents. Mg+H2SO4⟶MgSO4+H2 CaCl2+Na3PO4⟶Ca3(PO4)2+NaCl NaHCO3⟶CO2+NaOHNaHCOX3⟶COX2+NaOH AgNO3+NaCl⟶NaNO3+AgCl
Single replacement Double replacement Decomposition Double replacement
Determine where to dispose of each type of waste. unused solid reagent broken flask titrant solution syringe tips
Solid waste container Box lined with puncture resistant bag Nalgene bottle with cap Sharps container
Which property is the basis of the purification technique recrystallization?
Solubility
Determine when you should remove your goggles in the lab room.
When everyone in the room is done handling any chemicals or glassware
What is the equivalence point of a titration?
When the amount of acid and base are equal.
When should you start a new chemical waste container in the lab?
When the contents of the current container are a couple inches below the brim of the container
If a pH meter is not able to give an accurate measurement, it may need to be--. This process requires---
calibrated, two buffers of known pH.
When an alarm sounds in the laboratory, it is important to respond____and remain___Listen for any other instructions, turn off any___in use, and be prepared to leave immediately.
calmly, quiet, equipment
An ion is a---version of an atom that is formed by---compared to the atom.
charged, losing or gaining electrons
What is the name of the compound with the formula of Cr2S3?
chromium(III) sulfide
centimeter
cm (Length)
Suppose you are given the mass of each element in a compound sample. To calculate the empirical formula, start by---using---Then,---by---
converting the mass of each element to moles, each element's molar mass., calculate the ratio between the elements, dividing the moles of each element by the smallest number of moles present.
After assembling a gravity filtration apparatus, begin the separation of a mixture by--it into the filter paper. Pour the entire contents of the mixture into the filter paper,--the solid in the filter paper if needed to speed up the filtration. After all the liquid has drained through the filter paper, finish by rinsing the solid with---
decanting, stirring,solvent
When performing an addition or subtraction calculation, significant figures in the calculated result are dictated by the__of the measured numbers. The calculated result should have___the measured number in the calculation with the fewest___
decimal places, the same number of digits past the decimal point as, digits past the decimal point
In general, which characteristics are necessary for a location to be suitable for chemical storage?
dry, dark, cool
Identify the safety equipment designed to deal with each emergency listed. chemicals in eyes fire on a person cuts or minor burns chemicals on clothes large fire on the benchtop
eyewash station fire blanket first aid kit safety shower fire extinguisher
If you drop or break glassware in lab, first___ Then,___ Finally, place all that material into the__
get thick gloves or dustpan carefully collect all the broken glassware broken glass container
Changing gloves often will minimize the spread of chemicals. To properly remove gloves, first,___, and then,____. Then insert___between the interior edge of the second glove and the skin, and remove the second glove.
grasp the exterior of one glove with a gloved hand, peel off the first glove, a bare finger
The purpose of the best-fit line on an experimental scatter plot is to___The best-fit line allows us to---
identify any linear trend in scattered data. predict behavior between measured data using its slope.
A balloon is inflated outside on a cool morning. As the temperature rises, reaching its peak in the afternoon, the volume of the balloon will---. As the temperature cools down again in the evening, the volume of the balloon will---
increase, decrease PV=nRT
The relationship between pressure and volume of a gas is---so that as volume decreases, pressure---
inverse, increases.
A kilogram is defined as 1000 grams. This number___which means that it has___significant figures.
is an exact number, infinite
At the melting point, the solid form of a substance----the liquid form of the substance.
is in equilibrium with
In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent__in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at___. Using a___, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add___in order to dissolve the solid.
just until it covers the sample, a low setting and increasing gradually, pipet, as little solvent as possible
kilogram
kg (mass)
After a recrystallization, a pure substance will ideally appear as a network of___. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more
large crystals, slowly
Magnesium reacts with oxygen in the air when---Unlike other reactions, you should not----this reaction.
lit with a Bunsen burner, look directly at
milliliter
ml (volume)
The Law of Conservation of Energy states that---An example of the Law in the laboratory is---
no energy can be created or destroyed, only transferred or transformed., the water in a calorimeter absorbing heat given off by a reaction or hot object.
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the---end of the tube down. Continue tapping until the sample---Then, with the---end of the tube down, tap the sample down slowly or---to move the sample down faster. Finally, make sure that you can see---in the magnifier when placed in the melting point apparatus before turning on the heat.
open, is a couple millimeters high, closed, drop the tube into a longer tube, some or all the solid
Identify the equipment best suited for extinguishing each type of fire. small benchtop fire large fire on floor clothing fire
overturned beaker fire extinguisher fire blanket
When using the Tare function on a balance, start by___Then,___ to cancel out that mass. Finally,___and record the mass of your sample.
placing the glassware on the balance., press the Tare/Zero button, add your sample to the glassware
Calculate the volume of a box, in cubic centimeters, which is 423 cm long, 12 cm wide, and 25 cm high. Report your answer with correct significant figures in cubic centimeters.
130000 volume of the box=423 cm×12 cm×25 cm=130000 cm3
The rough melting point of an unknown compound is measured of 158-166°C, and a standard sample with literature melting point of 165-167°C was selected. What temperature plateau should be set for the instrument to measure the exact melting point of the unknown sample?
145 °C The plateau should be set 20 °C below the melting point of the standard sample
What is the correct way to report the length of the rectangle in centimeters?
15.60 cm
What is the correct reading of the volume in the pictured buret?
17.32
Complete the electron configuration of a calcium atom by selecting the correct orbitals.
1s22s22p63s23p64s2
Consider the given graph of an object's mass and volume. What is the density of the object, in g/mL?
2 slope=4−2/2−1
Potassium hydrogen phthalate is ____________.
A primary standard
When a known quantity of compound, at a known concentration, is added to a known volume of another compound to determine the concentration of the latter, the process is referred to as _____________.
A titration
To convert between units, you need to know the relationship between units. For example, one mile equals 5280 feet. This relationship can now be used as a conversion factor, set up as required by the question. For each conversion, choose the correct arrangement of the conversion factor and complete the calculation. 1. Convert 7860 feet to miles 7860 feet×( A )( B ) 7860 feet= miles 2. Convert 0.565 miles to feet 0.565 miles×( C )( D ) 0.565 miles= Ft
A:1 mile B:5280 ft =1.49 C:5280ft. D:1mile =2983
How should students prepare to use chemicals in the lab?
Become familiar with the chemicals to be used, including exposure or spill hazards. Locate the spill kits and understand how they are used.
Determine when to put on disposable gloves for work in the lab.
Before handling any glassware or chemicals for the experiment
When using a pH meter to monitor a stirring reaction mixture, where should you place the pH sensor electrode?
Between the stirring vortex and the side of the glassware
What are the best practices while sharing a lab balance with other students?
Brush off any chemical dust around the balance after each use., Alert your TA or instructor about any issues with the balance.
Which compounds could be represented by the empirical formula CH2?
C3H6 C2H4 C8H16
What is the name of the compound with the formula of CS?
Carbon monosulfide
When using a properly stabilized balance, how should you ensure that you get the most accurate mass reading possible?
Close the side shields on the balance during reading. Measure the mass of the sample at room temperature.
When inputting a formula into Excel or other spreadsheet software, what components are required for the formula to function properly?
Closing parentheses for any opening parentheses, An equal sign at the beginning of the formula
What color is phenolphthalein when the solution is acidic?
Colorless
For each reaction, determine whether it is an example of combustion or not. 2NO+O2⟶2NO2 2N2O5⟶4NO2+O2 C+O2⟶CO2 CO2+4H2⟶CH4+2H2O 2C2H6+7O2⟶4CO2+6H2O
Combustion Not combustion Combustion Not combustion Combustion
Determine whether the given compound name or formula contains a polyatomic ion. KCN Calcium hydroxide NH4Cl Magnesium sulfate SO3 Sodium phosphide
Contains a polyatomic ion Contains a polyatomic ion Contains a polyatomic ion Contains a polyatomic ion Does not contain a polyatomic ion Does not contain a polyatomic ion
A 7.298 g sample of copper reacts with oxygen, forming a copper oxide. The final mass of the copper oxide is 8.217 g. What is the formula of the copper oxide?
Cu2O 7.298 g×1 mol/63.546 g=0.1148 mol Cu 8.217 g−7.298 g=0.919 g O 0.919 g×1 mol/15.999 g=0.0574 mol O 0.1148 mol Cu/0.0574 mol O=2
The equation to calculate density is___, where D is the density, m is the____, and V is the ___
D=m/V, mass, volume
When equal moles of an acid and a base are mixed, after reaction the two are compounds are said to be at the _______________.
Stoichiometric point
Suppose that two students perform a titration experiment multiple times, resulting in the average concentrations reported here. Student A 0.125 ± 0.008 M Student B 0.12 ± 0.03 M The more precise work was done by---because---
Student A, that student's data has a smaller standard deviation.
Read each statement regarding food and beverages in the lab and determine if each is true or false. Food items should not be brought into the lab. Tobacco products of all kinds are prohibited in lab. Chewing gum is okay in the lab as long as you don't blow bubbles. Beverages are allowed in lab as long as they are in containers with lids.
T T F F
What are examples of solutions in your everyday life?
Tea, Rubbing alcohol, Vinegar, Mouthwash
Identify the term that matches each description. A measure of the amount of thermal energy in an object Energy that is transferred from one object to another The energy needed to raise the temperature of 1 gram of a substance by 1°C
Temperature Heat Specific heat
You can separate a mixture of sand and copper(II) sulfate pentahydrate using filtration. What difference in properties enables the separation of the two solids by filtration?
The hydrate is soluble in water but the sand is not.
Under what conditions should a student inform the instructor of a lab injury?
The instructor must be informed of all laboratory injuries
In the Ideal Gas Law lab, how is the temperature of the hydrogen gas determined?
The temperature of the water bath is measured after the reaction, which is assumed to be the same temperature as the gas.
How does the titration curve of a diprotic acid differ from that of a monoprotic acid?
There are two equivalence points.
What characteristics should a good sample for melting point determination have?
Thoroughly dry, Solid phase, Small particles
Determine the best way to deal with each of the following items that may dangle into the way during lab work. flowy sleeves long earrings loose bracelets long necklaces long hair
Tie back or secure Remove Remove Remove Tie back or secure
The liquid dispensed from a burette is called ___________.
Titrant
What needs to be included in the label for each axis of a graph?
Units of quantity displayed on axis Name of quantity displayed on axis
What is the main precaution to take if a Gas Cylinder sign is present in the lab?
Visually check that the gas cylinder is restrained but keep a safe distance from it.
What should you do every time before you leave the lab?
Wash your hands. Remove your lab coat, if you are wearing one. Remove your gloves.
Determine the safest option in the lab if you need your vision to be corrected.
Wear corrective glasses or lenses under your safety goggles for the whole experiment, but always check with your TA or Instructor for your school's policy
What is the last step of any spill cleanup procedure?
Wipe down the affected area with detergent and water.
Which is NOT a good source of information about the hazards that affect waste disposal in a chemistry lab?
Your lab partner
Predict the products of hydrochloric acid reacting with zinc metal.
ZnCl2 H2
Suppose you mix two solutions in a test tube and the test tube becomes hot. This is---because---
a sign of a chemical reaction, chemical changes can release heat.
Once the vacuum filtration set-up is complete, start by---in the filter funnel. Then,---the mixture---
adding a small amount of water, slowly decant, into the middle of the filter paper.
