Question

Gas pressure is caused by: A) barometers B) temperature C) gas molecules condensing into a liquid D) gas molecules hitting other gas molecules E) gas molecules colliding with surfaces 7) 8) What is the molarity of a solution that results when 21.3 g of (NH4)3PO4 (MM- 149 g/mol) is dissolved C) 0.357 M E) 1.61 x 10- water and brought to a total volume of 250.0 mL? D) 85.2 M B) 2.28 M A) 0.572 M 9) What is the mass (in grams) of NO that could be obtained from 15.5 g of N204 IMM 92.0 g/mole] an 4.68 g of N2H4 [MM 32.0 g/mole] when they react? The balanced chemical equation is; 2 N204+ N2H4 6 NO+ 2 H20 E) 5.04 B) 4.38 D) 26.3 A) 30.0 C) 15.2 10) Name the following compound Mg(NO3)2 A) magnesium(lI) nitrite B) C) magnesium dinitrate D) magnesium nitrate E) magnesium nitrite (II) nitrate 11) What is the mass of 1.50 moles of NaCI? A) 87.7 g B) 42.0 g C) 9.03 x 1023 g D) 39.0g E) 58.5 g 12) What is the molecular geometry of NO3? A) bent or angular B) trigonal pyramidal C) trigonal planar D) tetrahedral E) T-shaped 13) When solid ammonium chloride, NH4CI dissolves in water, the temperature of the solution decr reaction is NH4CI(s)NH4 (aq) +Cl-(aq) We can conclude which of the following statements is true? A) The reaction is endothermic and △H < 0 B) The reaction is exothermic and △H < 0 C) The reaction is thermoneutral and ΔΗ-0 D) The reaction is endothermic and Δ H > 0 E) The reaction is exothermic and AH>0 14) Which molecule below is NOT polar? A) HF B) SO2 C) H20

Answer 1

7. Gas pressure is caused by

E) gas molecules colliding with surfaces. Greater the collisions greater will be the pressure of the gas.

8. A) 0.572 M

9. C) 15.2 g

10. The name of the compound Mg(NO3)2 is

D) Magnesium nitrate

11. A) 87.7

7. Gas pressure is caused by E) gas molecules colliding with surfaces. Greater the collisions greater will be the pressure of the gas. 8. A) 0.572 M 9. C) 15.2 g 10. The name of the compound Mg(NO3)^2 is D) Magnesium nitrate 11. A) 87.7 \r\n mass of (NH_n)_3 po_4 = 21.3 g therefore no of moles of (N H_n)_3 po_4 = 21.3 g/149 g/mol = 0.143 mol volume of the solution = 250 m L = 0.25 L therefore Molarity of the solution = no of moles of solution/volume of solution in L = 0.143/0.24 = 0.572 M 9) 2 N_2 o_4 + N_2 H_4 rightarrow 6 NO + 2 H_2 O Given, mass of N_2 O_4 = 15.5 g therefore moles of N_2 O_4 = 15.5 g/92 g/mol = 0.168 mol mass of N_2 H_4 = 4.68 g