Chemistry Regent - Aug 2015 Q41-50

A mixture consists of sand and an aqueous salt solution. Which procedure can be used to separate the sand, salt, and water from each other?

• Evaporate the water, then filter out the salt. 
• Evaporate the water, then filter out the sand. 
• Filter out the salt, then evaporate the water.
• Filter out the sand, then evaporate the water

An aqueous solution has a mass of 490 grams containing 8.5  103 gram of calcium ions. The concentration of calcium ions in this solution is 

• 4.3 ppm
• 8.5 ppm
• 17 ppm 
• 34 ppm 

 A sample of hydrogen gas at 2.0 atmospheres and 273 K occupies a volume of 5.0 liters. The gas sample is completely transferred to a 10.0-liter sealed, rigid container. What is the new pressure of the gas sample when the temperature returns to 273 K? 

• 1.0 atm
• 2.0 atm
• 3.0 atm
• 4.0 atm

Given the equation for a system at equilibrium, if only the concentration of N₂(g) is increased, the concentration of 

• NH₃(g) increases
• NH₃(g) remains the same 
• H₂(g) increases
• H₂(g) remains the same 

A hydrocarbon molecule has seven carbon atoms in a straight chain. There is a double bond between the third carbon atom and the fourth carbon atom in the chain. The IUPAC name for this hydrocarbon is 

• 3-heptyne
• 4-heptyne
• 3-heptene
• 4-heptene

Which type of reaction is represented by this equation? 

• addition
• fermentation
• polymerization
• substitution

Given the diagram representing an incomplete electrochemical cell, solid copper will be deposited on one of the carbon electrodes when the wires are connected

• each other
• a battery
• a switch
• a voltmeter

What is the volume of 0.30 M NaOH(aq) needed to completely neutralize 15.0 milliliters of 0.80 M HCl(aq)? 

• 3.6 mL
• 5.6 mL
• 20. mL
• 40. mL

Which equation represents a spontaneous transmutation?

• 1
• 2
• 3
• 4

Which particle has two neutrons?

• 1
• 2
• 3
• 4