The table below gives the concentration of some ions in the sample. The mole mol is the amount of a substance that contains the same number of particles as atoms in exactly 12 grams of carbon12. Molarity is also the number of millimoles of solute present in exactly 1 ml of. Im in week 2 of college chemistry and i am completely lost on how to work out one of my chapter problems. Formula mass since molecules are made of atoms, the relative formula mass is the sum of the masses of the atoms it is made of. A student does an experiment to find the formula of zinc oxide. Molecular formula shows all the atoms present in a molecule. Calculate the number of moles and the mass of the solute in each of the following solutions. Data booklet scientific calculator, ruler instructions tt use black ink or ballpoint pen. Write the coefficient of each substance in equation below the formula represents moles reacted or produced 6. Using moles to balance equations given masses for the following equation. They believed that, for example, if one molecule of carbon dioxide co 2 contained 1 carbon atom and 2 oxygen atoms, then the ratio of carbon atoms to oxygen atoms is 1. Use that knowledge to answer all questions in this examination. Exercise 11a calculations based on concentrations in solution.
In other words, 1 mole of vo3 gains 3 moles of electrons its oxidation number would decrease by 3 units. The mole the mole and concentration of solutions bbc bitesize. How do we work out the number of moles of a compound. It covers everything the students need to know about the calculations topic, including. Concentration 1 x volume 1 number of moles 1 concentration 2 x volume 2 number of moles 2. Calculating molar concentrations from the mass of solute. Use the relative atomic masses listed in your data book. The amount of substance is measured in units of moles.
An engaging lesson presentation 80 slides and associated worksheets that uses a combination of exam questions, quick tasks and quiz competitions to help the students to assess their understanding of the topics found within topic 3 quantitative chemistry of the aqa gcse chemistry specification specification point c4. Fill in the boxes at the top of this page with your name, t centre number and candidate number. The empirical formula of a compound is the simplest form of the ration of the atoms of different elements in it. The mole concept applies to all kinds of particles. Give the formula of each cobaltcontaining species formed.
Section b answer all of the questions below in the space provided on pages 16 to 20 of this booklet. Aqa 19 gcse chemistry science quantitative chemistry. Base your answer to the following question on the information below and on your knowledge of chemistry. The constant k is called the boltzmann constant in honor of austrian physicist ludwig boltzmann 18441906 and has the value k 1. Therefore, you can find the density through a search and volume through various methods such as displacement or just measuring it. Work out the moles of the known substance using concentration molesvolume 2. Mole and equations alevel chemistry revision notes. N5 calculations book1 chemistry teaching resources. Heres how you would calculate the amount of grams you need. Exercise 4a calculation of the number of moles of material in a.
The mass, number of moles, concentration or volume of a substance can be calculated easily if you learn two formula triangles. The two types of concentration used commonly are moldm3 and gdm3. Convert between the amount of substance in moles and the number of atoms, molecules or formula units. If you are given the amount of material you need in. The following tests were carried out to identify the ions present. Some questions may require the use of the 2011 edition reference tables for physical settingchemistry. If we know the mass or moles of one substance, we can use this to work out either the theoretical. Cambridge international examinations cambridge ordinary level. Turn to the last page and fold it along the perforations. The mass, number of moles, concentration or volume of a substance can be. The mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon12.
Ua008883 workbook for gce students moles, formulae and equations edexcel advanced gce in chemistry 9080 edexcel advanced gce in chemistry nuffield 9086 issue 3 october 2004 1 structure of the atom the atom is composed of electrons, neutrons and protons. Mole concept study material for iit jee askiitians. The 2nd booklet will be questions extracted from previous exam papers n5, standard. The ideal gas law is generally valid at temperatures well above the boiling temperature. The number of moles of hydrogen iodide formed at t seconds was a 0. You are to answer all questions in all parts of this examination according to the directions provided in the examination booklet. The maximum mark for this examination paper is 90 marks. Explain why the total thermal energy of a sample containing 22. Quantitative units of concentration introductory chemistry 1st. Exercise 4d calculation of the number of moles of gas in a given volume of that gas 43. Information tt the total mark for this paper is 80.
Physical setting chemistry wednesday, june 20, 2018 9. Some questions may require the use of the 2011 edition reference tables for physical setting chemistry. Within the booklet are a range of different activities for students to work through to help them remember the content. It is important because if we take the molar mass of any substance, then it has 6. Moles, formulae and equations edexcel advanced gce in. The ideal gas law can also be written and solved in terms of the number of moles of gas. You have to remember the relative mass of, and the electric charge on. Given enough information, one can use stoichiometry to calculate masses, moles, and percents within a chemical equation. Mole calculations formula mass and mole calculations. Mole calculations the mole and concentration of solutions. The concentration c of a solution is usually expressed as the number of moles n of solute dissolved in one litre of solution and the units are mollitre mol l1.
Calculate the number of moles present in 500cm3 of nacl of. What is the concentration of a solution containing. Calculating a quantity in moles from a number of particles the calculation notes n the quantity in moles n the number of particles l avogadros constant, 6. If you have a dozen carrots, you have twelve of them. Molarity m is defined as the number of moles of solute divided by the number of liters. For example, the molecular formula of phosphorusv oxide is p4o10, whereas its empirical formula is p2o5. Fill in the boxes at the top of this page with your name, centre number and candidate number. Number of moles of dna in 2 picogram given weight mol wt 2 x 1012 1. The ideal gas law states that pv nkt, where p is the absolute pressure of a gas, v is the volume it occupies, n is the number of atoms and molecules in the gas, and t is its absolute temperature. Energy from a fuel mass x specific heat capacity x change in temperature. Mole fraction fraction of the substance in the mixture expressed in terms of mol is called its mol fraction x e.
Molarity, m moles of solute per liter of solution a abc. A mole is a unit to count the number of atoms, ions or molecules. Solution w is sulfuric acid of unknown concentration. A separate answer sheet for part a and part b1 has been provided to you.
Aug 06, 2016 the easiest way to calculate mass is probably through the density formula which is that density rho massvolume. Calculate the molar concentration of ethanol in an aqueous solution that contains. Write given numbers of moles of each reactant or product above formula. Common calculations chemistry lab resources for chm 1xx. A clean copy of the chemistry data booklet is required for this paper. Molarity, m moles solute per liter solution n moles. The aim of the booklet is to help students to practise their skills in the areas of formulae, equations and.
The booklet gives examples for students to work through. Chemistry candidate session number higher level paper 2. Centre number candidate number edexcel gce chemistry. Proportionally we should have a lower amount of moles. C3 revising booklet quantitative chemistry combined higher. The gram formula mass of a substance is known as the mass of one mole. Formulae, equations and amounts of substance the mole is the key concept for chemical calculations definition. May 10, 2014 this is the first video in a series that will cover the amount of substance topic in the aqa alevel chemistry spec. Pv nrt, where n is number of moles and r is the universal gas constant, r 8. How many moles and millimoles of benzoic acid mwt 122. We can find the number of moles by the division of the reference. Learn to determine specific concentrations with several common units. There are some sections involving multistep calculations.
Answer the questions in the spaces provided there may be more space than you need. A balanced equation tells us the number of moles of each reactant. We simply add up the mass numbers of the atoms in their formulas. Burn a known mass of magnesium and from this calculate the number of moles of mg. Your answer sheet for part a and part b1 is the last page of this examination booklet. It is the measure of the amount of substance that you have. You start with the formula from page 3 of the data booklet n cv. Molar analytical concentration is the total number of moles of a solute, regardless of its. The booklet gives examples for students to work through to help build their confidence. Molarity m is a useful concentration unit for many applications in chemistry. Pearson centre number candidate number edexcel gce chemistry. Aqa gcse chemistry topic 3 revision quantitative chemistry. Work out the concentration of the unknown substance using concentration molesvolumes example. So if we wanted to make 100 molecules of carbon dioxide.
Understanding molarity and how to calculate it easily. Cfe higher chemistry unit three chemistry in society. This number of particles atoms or molecules or ions per mole is called avogadros number and is numerically equal to 6. Working out the moles of the unknown substance using the molar ratio in the reaction equation 3. C3 revising booklet quantitative chemistry triple higher. Convert all given masses of reactants or products to moles. Jun 12, 20 ii calculate the number of moles of silver ions in the 10. Molar mass of any elementcompound is defined as the atomicmolecular weight expressed in grams. This is a revision booklet aimed at the new 2016 science gcse. Calculate the number of moles present in 500cm3 of nacl of concentration 0. Number of moles of gases standard molar volume at stp 22. The video briefly looks at the mole and then how to utilise equations to work. Calculate the concentration of the following solutions in mol l1.
The aim of the booklet is to help students to practise their skills in the areas of formulae, equations and simple mole equations. Number of dna molecules moles x avogadro s number 6. Mole concept and problems solving approaches in life sciences. Mole is the mass of the substance expressed in grams. May 26, 2017 data booklet scientific calculator, ruler instructions use black ink or black ballpoint pen.
The number of moles of the reactants must equal the number of moles of the products. The molecular formula tells the actual number of each kind of atom in one molecule of the substance. Calculate the concentration in moles per litre of a solution containing. Relative atomic mass is the average mass of one atom. From the equation, 2 mol of naoh reacts with 1 mol of na 2 so 4, so 0. Concentration has the unit mol l1 moles per litre this means the volume in this equation must be in litres as well.
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