CHEMISTRY Guess Paper – 2013 Class – XI Subject - CHEMISTRY MAX MARKS=90 ……………………………………………………………………………………… General instructions: All questions are compulsory. Marks for each question are indicated against it. Questions number 1to 8 are very short –answer questions‚ carrying 1 mark each. Answer these in one word or about one sentence each. Questions number 9 to18 are short –answer questions‚ carrying 2 marks each. Answer these in about 30 words each. Questions number19 to27
Premium Periodic table Alkaline earth metal Quantum mechanics
= 23.2 ˚C Enthalpy change: Now using all the variables obtained we can calculate the enthalpy change for the reaction using (∆H) = mc∆T Now‚ Mass of copper (II) sulfate (CuSO_4) = 25 〖cm〗^3 Temperature change (∆T) = 23.2 ˚C Specific heat capacity of water = 4.18 J g-1 k-1 Using the equation provided above‚ we can plug in the values necessary to find the enthalpy change (∆H) = 25 〖cm〗^3 X 23.2 ˚C X 4.18 J g-1 k-1 (∆H) = - 2424.4 J Now to find the enthalpy change per mole or (kJ/Mol)
Premium Chemistry Sulfuric acid Copper
systems to determine the change in enthalpy of the solution‚ which can b related to the change in internal energy of the solution. The van ’t Hoff isochore relates the equilibrium constant of a chemical reaction at one temperature to the equilibrium constant of the same reaction at a different temperature‚ allowing it to be worked out for all temperatures if it is known for one. The experiment used the solution of toluene and naphthalene to determine the change in enthalpy. The mole fractions and the tempterature
Premium Thermodynamics Benzene Temperature
repeating patterns within the periodic table & regular pattern in a property as you go from left to right across a period. Electrical conductivity - metallic elements good conductors Density - increases to a maximum in group 3‚ then falls. Ionisation enthalpy - Group 1-troughs - Group 0-peaks. Melting and boiling points - peaks group 4 - increases up to Group
Premium Atom Oxygen Periodic table
The system uses refrigerant 134a and water as the working fluids. The power input of the system was measured. The rate of heat output and the coefficient of performance are to be determined. A sketch of the vapor-compression cycle on a pressure-enthalpy diagram is also to be presented. In order to perform this analysis the temperatures at the inlet and outlet of the condenser and evaporator were measured for both the refrigerant and the water. The flow rate of the refrigerant through the system
Premium Thermodynamics Heat Heat pump
Chemistry Module Six: Thermochemistry and rate Study sheet for the test G.01: Thermo-chemistry I. Temperature and Thermal Energy Temperature is a measure of the average kinetic energy of the particles in a sample of matter. The greater the avg. kinetic energy of the particles in a sample of matter‚ the higher the temperature of that matter. Some temperature scales are Fahrenheit‚ Celsius and Kelvin. Thermal energy is the measure of the total kinetic energy in a sample. And Temperature
Free Thermodynamics Energy Temperature
Data collection and processing Qualitative observation Before * Blue solution of copper sulfate * Grey zinc powder During * Blue color solution changes to greyish black * Heat is given out‚ so the surroundings become hotter. After * Grey powder remains on the sides of the cup * Precipitate formed at the bottom of the cup List of chemicals and apparatus used Chemicals used Copper sulfate solution‚ 1 mol dm-3 25g of zinc powder Apparatus needed
Premium Thermodynamics Temperature Specific heat capacity
could measure the density of atoms with crude experiments. The second part of the experiment dealt with Solubility of large ions and their Hydration enthalpy. Hydration enthalpy is the enthalpy change when 1 mole of an ionic substance dissolves in a solution to give a solution of infinite dilution. (Jim Clark‚ 2010). (Jonathan Hopton‚ 2011) Hydration Enthalpy decreases (gets less negative) down a group‚ the Solubility of the group 2 metals also decreases down the group. Methods The method was followed
Premium Chemistry Periodic table Chemical element
Peroxodisulphate and Iodide practical – exemplar Skill A – Chemical Ideas Reaction between Peroxodisulphate and Iodide The reaction between peroxodisulphate and iodide ions is given by the following equation: S2O¬82- (aq) + 2 I- (aq) 2 SO42- (aq) + I2 (aq) The structure of the peroxodisulphate ion‚ with oxidation states‚ is shown below: (Structure) The changes in oxidation state within the reaction are as follows: Element Oxidation state in reactant Oxidation state in product Oxidised or
Free Chemical kinetics Chemical reaction
2. Why alkali metals used in photoelectric cells? 3. Due to which compound‚ ozone depletion is caused in Antarctica? 4. Which of the element among B‚ Al‚ C and Si :- a. Has the highest first ionization enthalpy? b. Has the most negative electron gain enthalpy? 5. c. Write the atomic number of the element present in the third period and seventeenth group of the periodic table. d. Out of the elements Cr (Z-24)‚ Mg (Z=12)‚ and Fe (Z=26)‚ identify the element
Premium Periodic table Chemistry Energy