Question

10. A student measured the density of copper. In 5 measurements, the density was found to be 8.42 g/cm2, 8.97 g/cm2, 8.54 g/cm, 8.62 g/cm, and 8.33 g/cm. The actual mass of the unknown sample should be 8.96 g/cm2. What would be the accuracy and precision of the measurements? (a) Low accuracy, low precision (b) Low accuracy, high precision (c) High accuracy, low precision (d) High accuracy, High precision (e) Insufficient information is provided. 11. The density of ethanol is 0,789 g/cm2. Calculate the mass of ethanol with a volume of 0.0882 m2. (a) 6.96 x 10 g (b) 6.96 g (c) 6.96 x 10' g (d) 6.96 x 102 g (e) 6.96 x 104 g 12. Consider the following mathematic operation: 3.441 x 4.821 +13.12-- 45.21 + 2.122= How many number of significant figures should be contained in the answer? (a) 2 (b)3 (c) 4 (d) 5 (e) 6 13. Determine the oxidation number of Mn in MnO4. (a) +4 (b) +5 (c) +6 (d) +7 (e) +8

Answer 1

Answer:-

These questions are answered by using simple concept of basic concepts of chemistry which involves the units and their measurements.

The answer is given in the image,

Answer: 10.com Low accuracy, low precision 11. 0-0.789 g/cm3 V=0.08820m3 -0.0082x106cm3 majs = dxv=0.789x0.0882x10-6 = 6-96X104, (e) 6.96*104 g is correct answer. 12. 3.441 X4,821+13.12 - 45.12=1-122 =16.59+13,12 -40.21 = 29.72 -40. 21 = 10.99 (C) 4 significant figure will be=4 13. Mnogo x + 4*(-2)=-1 G-02-1 x=+7 (d) 47 is correct answer.