Assignment (Chemistry subject)

Chapter 1- Molecular Reasons
14- what is the difference between a homogeneous and a mixture and a heterogeneous mixture? Give one example of each
22- Classify each of the following as a law or theory.
a- In a chemical reaction, energy is neither created nor destroyed
b- All matter is composed of atoms
c- When the temperature of a gas is increased, the volume of the gas increases
d- Gases are composed of particles in constant motion
26- which substance is a solid?
a- the helium in a balloon
b- dry ice
c- vegetable oil
d- shampoo
30- Classify each of the following changes as physical or chemical
a- the burning of butane in a lighter
b- the freezing of water
c- the bending of a copper rod
d- the fading of a brightly colored cloth upon excessive exposure to sunlight
34- Determine if any of the following data sets on chemical reactions are inconsistent with the law of conservation of mass and therefore erroneous
a- 8 grams of natural gas react with 38 grams of oxygen gas to form 17 grams of carbon dioxide and 19 grams of water
b- 5.7 grams of sodium react with 8.9 grams of chlorine to produce 14.6 grams of sodium chloride
36- A chemist combines 6 grams of hydrogen with 52 grams of oxygen in an explosive reaction that forms water as its sole product. All of the hydrogen reacts but 4 grams of oxygen remain. How many grams of water are formed?

Chapter 2- The chemist’s toolbox
16- Express each of the following in scientific notation:
a- 19,541,453 (population of New York state)
b- 6,873,370,698 (world population)
c- 0.00000000007461 m (length of a hydrogen-hydrogen chemical bond)
d- 0.000015 m (diameter of a human hair)
18- Express each of the following in decimal notation:
a- 6.022*10^23 (number of carbon atoms in 12.01 grams of carbon)
b- 3.00*10^8 m/s (speed of light)
c- 450*10^(-9) m (wavelength of blue light)
d- 13.7*10^9 yr (approximate age of the universe)
20- The distance from New York to Los Angeles is 2777 miles. Convert this distance into each of the following units:
a- Kilometers
b- Meters
c- Feet
26- Perform each of the following conversions within the metric system:
a- 2319 cm to m
b- 4912.5 g to kg
c- 23.1 cm to mm
d- 561 mL to L
28- Perform the following conversions between the metric and English system:
a- 4.92 in. to mm
b- 8779 yd to km
c- 87 ft to m
d- 3.8 in to cm
38- (Please see image from my textbook that I sent the writer, thanks)
42- A 3.80 mL sample of mercury has a mass of 51.4 g. What is the density of mercury in g/cm^3?
44- A thief plans to steal a bar of gold from a woman’s purse and replace it with a bag of sand. Assume that the volumes of the gold and the sand are 350 mL each and that the density of sand is 3.00 g/cm^3
a- Calculate the mass of each object
b- Would the woman notice a difference in the weight of her purse