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An aqueous solution is made by dissolving 29.4 grams of nickel(II) nitrate in 403 grams of water.
The molality of nickel(II) nitrate in the solution is m
5
.
When you take a bath, how many kilograms of cold water (10°C) must you mix with hot water
(50°C) so that the temperature of the bath is 35°C? The total mass of water is 180 kg. Ignore any
heat flow between the water and its surroundings.
An aqueous solution of sodium bromide, NaBr, contains 3.40 grams of sodium bromide and 17.4 grams of water.
The percentage by mass of sodium bromide in the solution is %.
The equilibrium mixture is found to contain 0.07, 0.11,0.03 and 0.03 moles of CO ,H2, CH4, H2O respectively for the reaction:
CO(g)+3H2(g)0. CH4=H2O(g)
You need to make an aqueous solution of 0.140 M potassium nitrate for an experiment in lab, using a 125 mL volumetric flask.
How much solid potassium nitrate should you add?
blank grams
In the laboratory you dissolve 18.5 g of nickel(II) bromide in a volumetric flask and add water to a total volume of 125 . mL.
What is the molarity of the solution? M
Given the population 3 5,7,9,11,13
How many samples can be made from the population with sample size of 3?
Calculate the mean of the sampling distribution
Compute the variance o the sampling distribution
What is the pH of the solution containing 0.20 M NH3 and 0.15 M NH4Cl?
Calculate the pH of a buffer made from 0.28 M HNO2 and 0.23 M NO2-. The Ka for HNO2 is 4.6×10-4
The students’ IDs and test answers are
stored in a file. The first entry in the file contains answers to the test in the form:
TFFTFFTTTTFFTFTFTFTT
Every other entry in the file is the student ID, followed by a blank, fol- lowed by the student’s responses. For example,
the entry:
ABC54301 TFTFTFTT TFTFTFFTTFT
indicates that the student ID is ABC54301 and the answer to question 1 is True, the answer to question 2 is False, and
so on. This student did not answer question 9. The exam has 20 questions, and the class has more than 150 students.
Each correct answer is awarded two points, each wrong answer gets one point deducted, and no answer gets zero
points.
Write a program that processes the test data. The output should be the student’s ID, followed by the answers, followed
by the test score, followed by the test grade. Assume the following grade scale: 90%–100%, A; 80%–89.99%, B; 70%–
79.99%, C; 60%–69.99%, D; and 0%–59.99%, F.
