Hi, guy. I've got some more chemistry questions if youd like to help! If you could explain any of them, that'd help too, thanks
1. A hydrogen-filled balloon was ignited and 2.00 g of hydrogen
reacted with 16.0 g of oxygen
How many grams of water vapor were formed? (Assume that water vapor is the only product.)
2. The mass ratio of sodium to fluorine in sodium fluoride is 1.21:1
. A sample of sodium fluoride produced 28.2 g of sodium
upon decomposition. How much fluorine
(in grams) was formed?
3. An automobile gasoline tank holds 20 kg of gasoline
. When the gasoline burns, 86 kg of oxygen
is consumed and carbon dioxide and water are produced. What is the total combined mass of carbon dioxide and water
that is produced?
4. A helium nucleus has two protons and two neutrons. How many electrons
would it take to equal the mass of a helium nucleus? (Express your answer using two significant figures.)
5. Silver has only two naturally occurring isotopes. The mass of silver-107 is 106.9051 amu and the mass of silver-109 is 108.9048 amu.
Use the atomic mass of silver to calculate the relative abundance of silver-107. Use the atomic mass of silver to calculate the relative abundance of silver-109
6. A solution of ammonia and water contains 1.40×10^25 water molecules
and 7.00×10^24 ammonia molecules
. How many total hydrogen atoms
are in this solution?
7. 1 mol of sand grains would cover the state of Texas to several feet. Estimate how many feet by assuming that the sand grains are roughly cube-shaped, each one with an edge length of 0.10 mm . Texas has a land area of 268,601 square miles.
8. If your body develops a charge of -10 (microcoulombs)
, how many excess electrons has it acquired? (Express your answer using two significant figures)
What is their collective mass? (Express your answer using two significant figures)
9. How many electrons are necessary to produce a charge of -1.1 C
? (Express your answer using two significant figures) What is the mass
of this many electrons? (Express your answer using two significant figures)
10. (density of neutron d= 4.0 x 10^14 g/cmcubed) Assuming that a neutron star has the same density as a neutron, calculate the mass in kg
of a small piece of a neutron star the size of a spherical pebble with a radius of 0.16 mm. (Express your answer using two significant figures)
11. Factor completely
3x(x – 2)^-5 – 3x^2(x – 2)^-6