Chemistry Answers

Consider the following generic chemical equation: 2A + 5B ➡️ C + 3D. If you react 4 units A with 10 units of B, which statement is true?

 Quinine (a non-volatile, non electrolyte) has the empirical formula C10H12NO.A sample of

quinine (0.162 g) was mixed with camphor (10.0 g) and the freezing point of the mixture was found to be 175.2 oC. The freezing point of pure camphor was determined to be 177.2 oC.

[Kf (camphor) = 40.0 oC Kg mol-1]

(a) Calculate the freezing point depression of the solution.

(b) Calculate the molality of the quinine.

(c) Calculate the moles of quinine.

(d) Calculate the molar mass of quinine

(e) What is the molecular formula of quinine?

How many liters of solution are needed to make a 1.66M solution containing 2.11 moles of potassium permanganate

At 200 °C, the concentrations of nitrogen, hydrogen, and ammonia at equilibrium are

measured and found to be [N2] = 2.12 M, [H2] = 1.75 M, and [NH3] = 84.3 M. Calculate

the equilibrium constant at the temperature given.

Why you should never heat a volumetric flask or add hot solution to it

in the sun hyrdogen atoms undergo nuclear fusion to produce Helim and -1.7 x 10^9 kj/mol of He how much energy can be obtained from 1.00 kg of helium

 Canadian (CANDU) nuclear reactors produce energy by nuclear fission of uranium-235. 

in + 235U → Kr + 14Ba + 3 in 

If the molar enthalpy of fission for uranium-235 is -1.9 x1010 kJ/mol, how much energy can be obtained from the fission of 1.00 kg of pure uranium-235? 

A sample of bauxite ore contains 7.71 x 1024 molecules of aluminum

oxide, Al20g. How many moles of aluminum oxide are in the sample?

What is the molar mass of magnesium

In the reaction Mg(OH)²+2HCl--->MgCl²+2H²0 you were given 15 grams of Mg(OH)² and 25 grams of HCl.Which of the two reactants is the limiting reagents? How much MgCl² will be produced in the reaction?