General Chemistry Answers

What is the molarity of the solution produced when 145 g of magnesium chloride is dissolved in sufficient water to prepare 2.75 L of solution with a density of 2300kg/m³? 

When copper metal is heated it reacts with a gas in air.

What is the chemical name of the product formed when copper reacts with

a gas in air?

(1 Point)

1.  A 10.0-liter flask contains  0.400 mole of H2, and 0.300 mole of  N2 at 20°C. 

(a) What is the pressure, in atmospheres, inside the flask?

(b) Calculate the mole fractions of the three gases?

Group 2: 25 mL CaCl₂

Trial Mass of filter paper Mass of solid + filter paper

1 0.65 g 1.48 g

2 0.64 g 1.57 g 

3 0.66 g 1.61 g

Our filtrate was a bit cloudy to start with, but didn't change at all when we added more of either starting material.

Based on the recorded notes from group 2, what alteration from the suggested procedure could account for the discrepancy in their data? Explain the evidence that led to your answer.

In order to test Billy's hypothesis, 6 groups of lab students were given the following rules to follow:

• Each group must perform the synthesis of CaCO₃ three times
• Each group will use the same amount of Na₂CO₃: 25 mL of a 0.5 M solution
• Each group will be assigned either 15, 25, or 35 mL of a 0.5 M CaCl₂ solution to use

Following these rules and the clues given in the puzzle, the groups worked together to come up with the following overall procedure to try and address both parts of Billy's hypothesis. 

Group 6's data differ greatly from the rest of the class. Based on the discussion of the suggested procedure and the the difference in their data, what step do you think group 6 may have forgotten? Explain your answer.