Q: A student needs to prepare $$250 mL of a$$ $$0.10 M $$NaCl solution. Which of the following is the correct calculation for the mass of NaCl (molar mass $$= 58.44 g/$$mol) required?

$$0.10 \times 0.250 \times 58.44$$

Q: Which of the following is the correct formula for calculating percent error in an experiment?

$$\frac{\text{Experimental Value} - \text{Theoretical Value}}{\text{Theoretical Value}} \times 100\%$$

Question 1

A student is preparing to perform a chemistry experiment that requires measuring the mass of a sample and recording the result with the correct number of significant figures. If the balance reads $$12.340 g$$, how many significant figures should the student report?

Accepted Answer

$$5$$

Question 2

During a laboratory experiment, a student measures the temperature of a solution as $$25.0^\circ C. If $$the thermometer used has markings every $$0.1^\circ C$$, what is the correct way to report this measurement?

Accepted Answer

$$25.0^\circ C$$

Question 3

A student needs to prepare $$250 mL of a$$ $$0.10 M $$NaCl solution. Which of the following is the correct calculation for the mass of NaCl (molar mass $$= 58.44 g/$$mol) required?

Accepted Answer

$$0.10 	imes 0.250 	imes 58.44$$

Question 4

Which of the following best describes the purpose of using a scientific calculator in the chemistry laboratory?

Accepted Answer

To ensure calculations are performed with correct significant figures and scientific notation

Question 5

A student is asked to convert $$0.00560 L to $$scientific notation. What is the correct answer?

Accepted Answer

$$5.6 	imes 10$$^{-3}$$

Question 6

In a laboratory report, a student records the following data: $$2.45 g$$, $$2.5 g$$, $$2.47 g$$, and $$2.46 g. $$What is the average mass, reported with the correct number of significant figures?

Accepted Answer

$$2.47 g$$

Question 7

A student is analyzing a chemical reaction and needs to determine the limiting reactant. Which of the following steps should the student perform first?

Accepted Answer

Convert all reactant quantities to moles

Question 8

Which of the following is NOT a required safety practice in the chemistry laboratory according to the syllabus?

Accepted Answer

Wearing open-toed shoes

Question 9

A student is asked to identify the number of significant figures in the measurement $$0.00450 g. $$What is the correct answer?

Accepted Answer

$$3$$

Question 10

If a student is absent from a laboratory session, what is the most appropriate action according to the course policy?

Accepted Answer

Contact the instructor to make special arrangements if needed

Question 11

A student is preparing a solution and needs to use a volumetric flask. Which of the following best describes the correct use of a volumetric flask?

Accepted Answer

To measure and deliver a precise volume of liquid

Question 12

Which of the following is a correct example of scientific notation for the number $$0.00032$$?

Accepted Answer

$$3.2 	imes 10$$^{-4}$$

Question 13

A student is asked to calculate the density of a liquid. The mass of the liquid is $$12.5 g $$and the volume is $$10.0 mL. $$What is the density?

Accepted Answer

$$1.25 g/mL$$

Question 14

Which of the following statements about lab safety is TRUE according to the course syllabus?

Accepted Answer

Eating and drinking are not permitted in the laboratory

Question 15

A student is required to submit a lab report. According to the syllabus, what is the penalty for submitting a report late?

Accepted Answer

10% deduction for each day late

Question 16

Which of the following is the correct formula for calculating percent error in an experiment?

Accepted Answer

$$\frac{	ext{Experimental Value} - 	ext{Theoretical Value}}{	ext{Theoretical Value}} 	imes 100\%$$

Question 17

A student is asked to classify a chemical reaction. Which of the following is an example of a decomposition reaction?

Accepted Answer

$$2H_2O_2 \rightarrow 2H_2O + O_2$

Question 18

If a student needs to determine the concentration of an unknown acid solution using titration, which of the following pieces of equipment is most appropriate for delivering the titrant?

Accepted Answer

Buret

Question 19

A student is required to use scientific notation in lab reports. Which of the following is the correct way to express $$4,500,000 in $$scientific notation?

Accepted Answer

$$4.5 	imes 10$$^{6}$$

CHEM 1120L: Introduction to Chemistry Laboratory – Syllabus and Course Structure

Guida di studio - Domande di pratica

Study guide - Flashcard