NURSING TEST

OCR A-level chemistry amount of substance Questions and answer What is a mole? the amount of a substance that contains as many particles of that substance as there are atoms in exactly 12g of carbon-12. 1 mole contains the Avogadro number of particles. what is avogadro's number? 6.02 x 10^23 moles= Mass / Mr what is water of crystallisation? water molecules that form an essential part of a crystalline compound what is a hydrated compound? a crystalline comp...

A-level Chemistry Definitions Questions and Answers isotopes atoms of the same element with different numbers of neutrons atomic (proton) number the number of protons in the nucleus of an atom mass (nucleon) number the number of particles (protons and neutrons) in the nucleus ion a positively or negatively charged atom or (covalently bonded) group of atoms (molecular ion) relative isotopic mass the mass of an atom of an isotope compared with one twelfth of the m...

OCR A level Chemistry Module 3 Questions and Answers Periods Horizontal rows on the periodic table Ionisation The removal of one or more electrons from an atom. First ionisation energy The energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions Equation for IE1 of Li Li(g) --> Li+(g) + e- Factors affecting ionisation energy -atomic radius -nuclear charge -electron shielding How does atomi...

AQA A level Chemistry Enthalpy Definitions Questions and Answers Enthalpy change of formation The enthalpy change when one mole of a compound is formed from its constituent elements in their standard states under standard conditions Bond dissociation enthalpy The enthalpy change when all the bonds of the same type are broken in one mole of gaseous molecules Enthalpy change of atomisation of an element The enthalpy change when one mole of gaseous atoms is formed from an element ...

AQA A-Level Chemistry Question Cards Questions and Answers What is meant by activation energy? The minimum energy that a particle must have in order for a reaction to occur; the energy (enthalpy) difference between the reactants and the transition state. What is an aldehyde? An organic compound with the general formula RCHO. What is an alkane and what isthe general formula for the alkanes? A hydrocarbon with C-C and C-H single bonds only. General Formula = CnH2n+2 W...

AQA A-Level Chemistry Past Paper Questions and Answers 1) Shake the final solution in the flask. 2)Ensure the bottom of the (liquid)meniscus is on the graduation mark. 3)Wash the wet rod into the flask. Read the following instructions that describe how to make up a standard solution of a solid in a volumetric flask. Answer the questions which follow. "Take a clean 250cm3 volumetric flask. Use the balance provided and a clean, dry container, to weigh out the amount of solid required. Ti...

AQA A-level chemistry chemical tests Questions and Answers test for Carbon Dioxide (CO2 ) turns limewater milky (sparingly soluble Ca(OH) 2 forms insoluble CaCO3 ) Chlorine (Cl2 ) test bleaches damp litmus paper (Cl2 reacts with water to form HCl and HOCl) Hydrogen (H2 ) test pops with a lighted splint Oxygen (O2 ) test relights a glowing splint Carbonate (CO 3 2- ) test add dilute acid; effervescence, carbon dioxide produced Sulfate (SO4 2- ) test add d...

OCR A Level CHEMISTRY PAPER 1 Questions and Answers Test for carbonates - add dilute HCL - it makes carbon dioxide test for carbon dioxide by bubbling it through lime water Test for ammonium ions -add sodium hydroxide -warm the mixture -hover damp red litmus paper over it , if it turns blue the ions are present Test for sulphate ionz (SO4 2-) - add dilute HCL - then add BaCl2 - BaSO4 is made which is insoluble in water so a white precipitate will be formed Test for...

AQA A-level Chemistry Thermodynamics definitions Questions and Answers Enthalpy of Formation The enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions, all reactants and products are in their standard states. Enthalpy of Combustion The enthalpy change when one mole of substance is burned completely in oxygen under standard conditions, all reactants and products in their standard states. Enthalpy of Atomisation The enthalpy...

AQA A Level Chemistry - Paper 3 Experiments Questions and Answers Make Up a Volumetric Solution 1. Weigh dry weighing boat 2. Place mass of solid into the boat and weigh accurately 3. Pour solid into a beaker. Reweigh empty weighing boat and calculate how much was transferred 4. Add deionised water and stir with glass rod until dissolved 5. Funnel into a volumetric flask 6. Make up to mark with deionised water until bottom of meniscus is on the mark 7. Stopper and invert to mix Ac...