2. to convert from a given mass in grams to the number of moles, you would multiply by which of the following:
a. 1/avagrado's number
b. avagrado's numer/1
c. molar mass/1
d. 1/molar mass
e. avagrado's number/molar mass
3. the average mas of one atom of iron is 55.85 amu. what is the mass of avagrado's number of atoms?
4. how many moles are there in one ounce (28.4 g) of pure gold? (atomic weigh; Au 197.amu)
5. how many atoms of sulfur are present in 155 grams of sulfur (use atomic weight 32.06 amu0
6. how many atoms are there in .0200 mol of nicotine, a yellow liquid?
use formula weight: 162.2 amu
7. how many molecules are there in 0.325 grams of aspirin. use formula weight aspirin 180.2 amu
8. how many moles of HCl can be formed when 2 mol of hydrogen gas react with chloine?
9. iron reacts with oxygen to form iron (III) oxide (Fe203). how many grams of product will be formed from 125.5 g of Fe (use atomic weight; Fe 55.85 amu; 16.00amu
14. according to the vsepr theory, if the valence electrons on a central atom are 3 bond pairs and one nonbonding pair, what will be the geometry or shape of this atom?
15. what kind of change does not alter the composition of the substance undergoing the change?
a. molecular
b. endothermic
c. exothermic
d. physical
f. chemical
16. which of the following about the bohr's model of the hydrogen atom is incorrect?
a. the lowest energy orbit has quantum number n=1
b. the highest energy orbits are furthest from the nucleus
c. in a transition fron the n = 3 to the n = 1, light is emitted
d. energy differences between energy levels can be calculated from the wavelengths of the light absorbed or emitted
e. the greater the energy difference between the two levels, the longer the wavelength of the light absorbed or emitted.
Tags: