Physical vs. Chemical change
Ice Melting.
Physical
_N2 + _H2 -> _NH3
N2 + 3H2 -> 2NH3
How many liters are contained in 3.65 moles of chlorine gas at STP ?
81.8 L chlorine gas
What is the mass of 2 moles of Sulfur?
64.12 grams of Sulfur
KMnO4 of each element
24.74% K 34.76% Mn 40.50% O
Boiling water into steam.
physical
_P + _O2 -> _P2O5
4P + 5O2 -> 2P2O5
How many moles are in 15 grams of lithium?
2.2 mol lithium
Aluminum is often used for the structure of light-weight bicycle frames. How many atoms of Al are in 20.00 grams of Al?
4.46 x 10^23 atoms Al
(NH4)3PO4
28.19% N 8.11% H 20.77% P 43.00% O
Hydrochloric acid reacts with Potassium hydroxide to produce salt, water, and heat.
Chemical
_Na + _H2O -> _NaOH + _H2
2Na + 2H2O -> 2NaOH + H2
how many moles are in 12 grams of potassium?
0.0307 Moles
Convert 5 moles of silicon tetrachloride into molecules of silicon tetrachloride
3.01 x 10^24 molecules silicon tetrachloride
Mg(NO3)2
16.39% Mg 18.89% N 64.72% O
Milk souring.
Chemical
_AgNO3 + _MgCl2 -> _AgCl + Mg(NO3)2
2AgNO3 + MgCl2 -> 2AgCl + Mg(NO3)2
how many moles are in 7 grams of sulfur?
0.218 Moles
How many moles is 518.0 grams of calcium chloride?
4.668 moles calcium chloride
H2SO4
H: 2.06%
S: 32.69%
O: 65.25%
Grass Growing.
Physical.
_CaCO3 -> CaO + _CO2
CaCO3 -> CaO + CO2
how many moles are in 102.7 grams of lithium?
14.8
Penicillin, the first of a now large number of antibiotics, has the formula C 16 H 18 N 2 O 4 S. Calculate the mass of 2.00 x 10^10 molecules of penicillin.
1.11 x 10^-11g C 16 H 18 N 2 O 4 S
NH3
N: 82.35%
H: 17.65%