2.4. A 2.3 L cylinder containing nitrogen gas at a pressure of 2.8 atm is connected to a 5.5 L
r containing nitrogen at 17.3 atm. What is the final pressure when both the cylinders have achieved equilibrium (reached the same pressure)?
6. An analytical procedure requires a solution of chloride ions. How many grams of BaCl2 must be dissolved to make 360 ml of 0.2 M Cl– ?
(M BaCl2 = 208 g/mol)
7. Find the concentration of chloride ions when 344.4 mL of 2.4 M NaCl is mixed with 364 mL of 2.9 M KCl?
8. A sample of an unknown gas had a density of 1.45 g/L at 20.5 °C and 1.2 atm. Calculate the molar mass of the gas.
(R = 0.08206 L·atm·mol-1·K-1)
12.(a) A 20.0 L container at 303 K holds a mixture of two gases with a total pressure of 5.00
here are 2.00 mol of Gas A in the mixture, how many moles of Gas B are present? (R = 0.0821 L • atm/(K • mol))
(b) The gas in a 250. mL piston experiences a change in pressure from 1.00 atm to 2.80 atm. What is the new volume (in mL) assuming the moles of gas and temperature are held constant?
(c) Small quantities of Oxygen can be produced by the decomposition of mercury(II) oxide as shown below. Typically, the oxygen gas is bubbled through water for collection and becomes saturated with water vapor. Atomic weight of HgO = 216.6 amu, Atomic weight of Oxygen = 32.00 amu)
2 HgO(s) → 2 Hg(ℓ) + O₂(g)
(i) Assuming that 3.05 grams of HgO was used in this reaction, determine the number of moles of oxygen gas formed.(According to the above chemical equation)
(ii) Assuming 310. 0 mL of Oxygen gas was collected at at 29°C, calculate the pressure of the Oxygen gas that was collected. (R = 0.0821 L • atm/(K • mol)
(iii) If the vapor pressure of water at this temperature equals to 0.042 atm, calculate the pressure reading of this experiment.
29.1) A hypothetical element exists as two isotopes: I = 42.00 amu and II = 49.00 amu. If the percent
bundance of isotope I is (1.94x10^1)%, what would be the calculated atomic mass (in amu)?
2) A hypothetical element exists as two isotopes: I = 78.00 amu and II = 84.00 amu. If the atomic mass of this element is found to be 80.33 amu, which isotope must be more abundant?
3) If the hypothetical polyatomic ion ThOM2- is called "thomite", what would be the formula and name of the acid formed by this ion?
4) How many atoms of hydrogen are there in a sample of (4.00x10^2) grams of NH3(g)?
5) How many O (oxygen) atoms are there in (6.40x10^2) grams of H3PO4?
6) How many moles of fluorine atoms are there in (5.80x10^2) grams of SF4?
7) When 3.50 g of titanium (Ti) reacts with oxygen, the resulting oxide compound weighs 5.84 g. What is the empirical formula of this oxide?
8) How many moles of molecules are there in (6.70x10^2) grams of CH4?
9) A chemical is found to be 80.0% C and the rest is H. If the molar mass of this chemical is known to be 90.2 g/mol, what is the molecular formula?
31.5 (5 points) There is H3PO4 available in stock solution that has an assay of 77% and a density
cific gravity) of 1.24. What is the molarity of this solution?
Using this solution how would 1 L of 2N solution be made.
6 (5 points) H3BO3 is needed to neutralize 20 ML of a 2N solution of NaOH. How much of the acid should I put in 40 ML of the water to exactly neutralize this solution?
7 (6 points) Describe how to make the solutions below :
20% w/v Salt in water.
20% v/v alcohol in water
20% w/w NaCl in water.
8 (three points) I have 0.6 g/dl solution of NaOH. What is M? Whan is N?
9 (six points) There are 3000mL of 3M NaOH. How much of the following do I need to neutralize? (watch your M’s and N’s
a) 3M H3PO4
b) 2M H2SO4
c) 1M HCL
10 (20 points) The following solutions of NaOH are mixed together 20ML of 3N, 40mL of 2N, 60mL of 1N, 80 mL of 4N, and 100mL of 5N.
a) What is the volume and normality of the final solution?
b) How much 4M sulfuric acid would I need to neutralize?
c) How much stock solution of sulfuric acid with an assay of 77% and a specific gravity of 1.14 would I need?
d) How many grams of HCl would I have to put in a 300mL solution of HCl in water to neutralize?
11 (3 points) How much 5N solution can I make with 98 grams of H3PO4 ?
12 (5 points) How much 5N solution of H3AsO4 can I make with 57 mL of stock solution that is 84% assay and 1.14 specific gravity?
13 (5 points) If we have a 4N solution of HCl that has 0.03645g of HCl in the solution, how many microliters of solution do we have?
14 (10 points) If we have 66mL of a solution of concentrated NaOH that has an assay of 88% and a specific gravity of 1.24, how much 3N H3AsO4 can be neutralized?
15 (ten points) If I have 17 mL of a 20% w/v solution of NaOH and I want to neutralize with H2SO4 that is available in a 4% w/v solution, how much of this solution will be required.
16 (ten points)
a) I have an 12mL of Ba(Cl)2 that is 78% assay that contains 8 grams of Ba(Cl)2. What is the specific gravity?
b) How many Moles of Ba(Cl)2 are there?
c) If I have 80 grams of NaOH in a liter of solution that is of an unknown specific gravity, can I calculate molarity and what is it?
d) What is the difference between molarity and normality?
e) I have 77 ml of 77% salt in water. How much 11% can I make?
32.I was wondering if you could help me step up my chem problems, i'm not sure how to begin
estion 1: Draven collected a 1ml sample from a local river. Draven added 99 ml of water to the sample. Draven then took 5 ml of the diluted sample, and determined the 5 ml sample to contained 10 mg of sodium chloride. what is the concentration of sodium chloride in the river?
question 2: how many grams of H2 could be produced when 13 g of H202 decompose?
question 3: how many molecules of carbon dioxide could be produced when 25 ml of a 0.8 M ethanol, c2h60, combusts with 5.18X10^23 molecules of oxygen? the unbalanced equation for the combustion of ethanol is given below: