Last name, First:________________________ Period:__ Seat___ Chem Homework-4 Due: 9/10/2019 Unit-2: Analyzing data

Show all steps of calculations and correct units. Before solving a problem, write the equation first and then substitute values from the word problems

1. Match the measurements with the unit in column B:

a. Length b. Width c. Mass d. Temperature e. Amount of substance f. Volume g. Time

Column-B ns kg pm mol K

2. Silver has an actual density of 10.3 g/cm3. Sam measured the density of a silver coin three times and obtained the following results:

Trial 1: 10.5 g/cm3 Trial 2: 10.4 g/cm3 Trial 3: 12.1 g/cm3

a. Write the density formula:________________________________________________________ b. When taking into account the values of all his trials, what is one possible error that may affect

Sam’s data readings in Trial-3 to be much higher than the rest?__________________________ _____________________________________________________________________________

c. Write the formula for calculating percent error ________________________________________

d. Calculate Sam’s percent error for trial # 2 (show all steps):______________________________ ______________________________________________________________________________

______________________________________________________________________________

3. Saturn is about 1,429,000 km from the Sun. How many milimeters is Saturn from the Sun? Calculate the answer using dimensional analysis and give your answer in scientific notation. All steps must be shown.

_____________________________________________________________________________________ _____________________________________________________________________________________

_____________________________________________________________________________________ _____________________________________________________________________________________ 4. You place a 28.95-g piece of gold in a 10-mL graduated cylinder. The level of the water rises 1.50 mL.

(Density = mass / volume).

a. What is the density of gold? (5pts) _________________________________________ _____________________________________ _________________________________________ b. What is the density of 2000 kg of gold?(5 pts)

_______________________________________ __________________________________________

5. Convert the following as indicated. (K = oC + 273) a. Bromine melts at -7.2°C. What is bromine’s melting point in kelvins?(4pts)

b. Chlorine melts at 172 K. What is chlorine’s melting point in °C? (4pts)

6. A student takes 520 mg of vitamin C every day. What is this mass expressed in grams?

a. 0.052 g b. 0.52 g c. 5.2 g d. 520,000 g

7. Which of the series of SI units is ordered from the smallest to the largest? a. pg, μg, kg, mg b. nL, L, mL, μL c. pg, ng, mg, g, kg d. mmol, μmol, nmol, mol

8. This graph indicates a graph generated from data gathered though a MNPS survey showing average 10th grade Math EOC test scores of students and the hours a student spends each day watching television (TV) or on their smart phone. The score range for test scores is 0-100 total points. The 12 students surveyed in this data were from 3 schools in the district.

1) What type of graph is shown in the Figure below? ____________________________ (1pts) 2) Correct the six- flaws found in this graph. Make your corrections directly on figure ______ (6 pts) 3) Based on the information given, ________________________________________ is the independent variable

and __________________________________ is the dependent variable. (1pts)

4) Based on this graph: a. How is Time spent on smartphone/ TV is

proportional to Math EOC scores?______ ___________ (1pts)

b. What score would a student get if they watched 10 hrs of TV a day?________ (1pts)

c. Are these data a good representation of Metro Nashville grade-10 students’ EOC Math scores? Yes or No [circle one] (1pt).

d. Explain your answer to c. stating supporting arguments:___________________________ ________________________________________________________________(1pts)

9. There are 3.9 nmol of sucrose molecules in a sugar grain.

a. How many nano moles of sucrose are in 40 grains of sugar? b. How many moles of sucrose are in 40 grains of sugar?

10. There are 13.2 moles of carbon [C] in 12.8 g. [FYI: 1 mol = 6.02 x 1023 atoms]

a. How many carbon atoms in 12 moles?

b. how many moles of carbon are found in 400g?