(c) Calculate the mass of water formed when 20 g of methane undergoes complete combustion. 6 Deduce the empirical formulae of the following: Moles and empirical formulae 1 Calculate the molar mass of these compounds. (Relative atomic masses H = 1; N = 14; O = 16; Mg = 24; S = 32; Ca = 40; K =39; Cr = 52; Fe = 56.) (a) calcium ethanoate, Ca(CH3CO2)2 (b) chromium sulfate Cr2(SO4)3 (c) magnesium hydroxide, Mg(OH)2 (d) potassium cyanoferrate(III), K3Fe(CN)6 2 When 2.4 g of magnesium
1. A solution containing 1.000M acetic acid (CH3COOH) and 1.000M ethyl alcohol (CH3CH2OH) at 150oC produced 0.171 mole/liter of the product ethyl acetate (CH3COOCH2CH3) when equilibrium was established. Determine Kc for the reaction. CH3COOH (aq) + CH3CH2OH (aq) CH3COOCH2CH3 (aq) + H2O (l) 2. Using the equilibrium constant from above, calculate the equilibrium concentrations of all the compounds in the reaction if 1.000M acetic acid is reacted with 2.000M ethyl alcohol.
Calculations involving Solutions (1) Answer the following questions on file paper. Remember to set out your working neatly and clearly, showing all necessary steps. Give answers to the appropriate number of significant figures. Use Ar values when required as given on your copy of the Periodic Table. 1) Calculate the number of moles in each of the following solutions:- a) 2.0 dm3 of 0.050 mol.dm-3 hydrochloric acid b) 50 dm3 of 5 mol.dm-3 sulfuric acid c) 10 cm3 of 0.25 mol.dm-3 potassium hydroxide [3] 2) Calculate the volume in cm3 of each solution that contains the following numbers of moles:- a) 0.00500 moles of NaOH with concentration 0.100 mol.dm-3 b) 1.00×10-5 moles of HCl with concentration 0.0100 mol.dm-3 c) 9.25×10-3 moles of KCl with concentration 0.250 mol.dm-3 [3] 3) Find the concentrations of the following solutions in both mol.dm-3 and g.dm-3:- a) 0.400 moles of HCl in 2.00 dm3 of solution b) 12.5 moles of H2SO4 in 5.00 dm3 of solution c) 1.05g of NaOH in 500 cm3 of solution [6] 4) In a titration, 25.0 cm3 of a solution of sodium hydroxide required 18.80 cm3 of hydrochloric acid of concentration 0.0500 mol.dm-3 for neutralisation.
Metal Name Mass of Metal Volume of water Initial temp. in calorimeter Initial temp. in beaker Final temp. of mixture Aluminum 34.720g 26.0mL 25.4°C 100.6°C 41.6°C Part II: Insert a complete data table, including appropriate significant figures and units, in the space below. Also include any observations that you made over the course of part II.
(Divide the mass of the liquid calculated above by the volume of the liquid.) * Trial 1: 10.16/8.12=1.25 * Trial 2: 10.61/8.26=1.28 * Trial 3: 10.38/8.52=1.22 Part II: Density of Irregular-Shaped Solid 3. Calculate the volume of the irregular-shaped solid for each trial.
i. What is the hydrogen concentration of a solution with a pOH of 3.7? j. What is the pH of a substance with a hydroxide concentration of 4 x 10-5? k. What is the hydroxide concentration of a substance with a pOH of 8.5?
The first example is calculating empirical formulas from percent compositions using the percents of the different elements. Empirical formulas of compounds are also determined through quantitative analysis by using the masses of each element in the equation3. Lastly, this experiment uses the method of finding empirical formulas through combustion analysis. The empirical formula of magnesium oxide is found from the combustion of magnesium1. The four chemical equations that result when metal magnesium is heated in a closed crucible that becomes gradually exposed to the oxygen in the air are shown in table
Purpose: The purpose of this lab is to verify Hess’s Law of Additivity of Reaction Enthalpies Chemical Reaction/Physical Reaction: 1.) Na(aq) + OH(aq) -> NaOH(s) 2.) NaOH + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 3.) Na(aq) + OH(aq) + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 List of Materials:Digital Thermometer, foamed polystyrene cups (3), 250 mL beaker,Weighing boat or small beaker, Graduated cylinders, 100mL(1), 25 mL(2),sodium hydroxide pellets, sodium hydroxide 2.0M, Acetic acid 1.0M and 2.0M. Safety Considerations: Always have safety goggles covering your eyes, do not inhale the fumes of chemicals used.
Controlled The controlled variables of the experiment were: A. The volume and concentration of the Hydrochloric acid. B. The concentration of the Sodium Hydroxide. Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube.
Calculate the molarity of an HCl solution if 20.0 mL of it requires 33.2 mL of 0.150 M NaOH for neutralization. 7. Calculate the molarity of a Ca(OH)2 solution if 18.5 mL of it requires 28.2 mL of 0.0302 M HCl for neutralization. The products are CaCl2(aq) and H2O. 9.