Section A (Answer ALL questions in this Section.) 1. Rubidium (Rb) and potassium belong to the same group in the Periodic Table. The relative atomic mass of rubidium is larger than that of potassium. (a) Explain whether rubidium is more reactive than potassium. (b) Write a chemical equation for the reaction between rubidium and water. (State symbols should be given.) (c) Suggest how rubidium can be stored safely in the laboratory. (d) Suggest ONE safety precaution for handling
Premium Chlorine Sodium hydroxide Acid
N10/4/CHEMI/SP2/ENG/TZ0/XX 88106105 CHEMISTRY STANDARD LEVEL PAPER 2 Thursday 11 November 2010 (afternoon) Candidate session number 0 1 hour 15 minutes 0 INSTRUCTIONS TO CANDIDATES • • • • Write your session number in the boxes above. Do not open this examination paper until instructed to do so. Section A: answer all of Section A in the spaces provided. Section B: answer one question from Section B. Write your answers on answer sheets. Write your session number
Premium Thermodynamics Sodium hydroxide Ammonia
Title: Stoichiometry Reaction Objectives: 1. To decompose sodium hydrogen carbonate (sodium bicarbonate) by heating. 2. To accurately measure the degree of completion of the reaction by analysing the solid sodium carbonate product. 3. To calculate amount of product with given amount of reactant. 4. To determine amount of heat release in the reaction. Results: Part 1: Thermal Decomposition of NaHCO3 Materials Mass (g) Clean and dry test tube 15.1632 Clean test tube + NaHCO3 17.1647
Premium Chemical reaction Chemistry Chlorine
Na2CO3(s)+CO2(g)+H2O(g). The was the only equation that matched up exactly with my data in terms of percentage. To start off with‚ when I balanced out the equation‚ I got 2 NaHCO3→ 1 Na2CO3(s)+ 1 CO2(g)+ 1 H2O(g). Therefore when I set up my stoichiometry problem I got 3.2 grams NaHCO3 over 1 x 1 mol NaHCO3 over 84.007g NaHCO3 x 1mol Na2CO3 over 2 mol NaHCO3 x 105.987g Na2CO3 x 1 mol Na2CO3. Hence‚ I multiplied 3.2 x 1 x 1 x 105.987 and got 339.1584. Afterwards‚ I divided 339.1584 by 84.007 and
Premium Chemistry Carbon dioxide Sodium hydroxide
volume. In this case‚ experimenters were given aqueous solutions of NaOH and CaCl2 in known molarities and then had them react with one another to yield a precipitate of Ca(OH)2. The precipitate was filtered out of the remaining aqueous solution of stoichiometry. In our case‚ all four tests yielded more mass than should have occurred. Experimenters attribute this completely evaporated from the filtered precipitate‚ which would add excess mass. By dealing with such small quantities of reagents‚ any small
Premium Chemistry Sodium Concentration
Q.1 Bond enthalpy of fluorine is lower than that of chlorine‚ why? Q.2 Give the IUPAC name of the following compound: (CH3)3-C-C-COOH ║ O Q.3 On increasing temperature‚ activation energy of a reaction decreases‚ why? Q 4 Which of the following is most effective electrolyte in the coagulative of AgI/Ag+sol? K2SO4‚ MgCl2‚ K4[Fe(CN)6] Q.5 Write the reaction when glucose is heated with excess of HI. Q.6 Which Xe compound has distorted octahedral shape? Q.7 What is the denticity of
Premium Oxygen Chemistry Carboxylic acid
Basic Stoichiometry PhET Lab rvsd 2/2011 Let’s make some sandviches! _ Introduction: When we bake/cook something‚ we use a specific amount of each ingredient. Imagine if you made a batch of cookies and used way too many eggs‚ or not enough sugar. YUCK! In chemistry‚ reactions proceed with very specific recipes. The study of these recipes is stoichiometry. When the reactants are present in the correct amounts‚ the reaction will produce products. What happens if there are more or less of
Premium Stoichiometry Hydrogen Chemical reaction
Ocean County College Department of Chemistry Stoichiometry of a Precipitation Reaction Submitted by Hendy Zelishovsky Date Submitted: 4/26/2012 Date Performed: 4/25/2012 Lab Section: Chem-180-DL1 Course Instructor: Dr. Cynthia Spencer Purpose
Premium Stoichiometry Yield Water
Isotopes and average atomic mass Isotope: element variations with different atomic mass but same atomic number Isotopic Abundance: the relative amount in which each isotope of an element Calculating: given 2 isotopes of an element [B: 10.01u] [B: 11.01u] 1) Given average atomic mass: 10.81u If given percentages‚ you can find average atomic mass by adding each portion 2) Set variables for unknown values Let x represent % abundance for 10/5 B Let 1-x represent % abundance for 11/5 B Calculate:
Premium Chemical element Neutron Atomic number
The calculations completed for this experiment include determining the amount of Na2CO3 needed to do a full reaction. This was calculated through stoichiometry calculations: Molar mass was first calculated for CaCl2*2H2O Ca = 40.078g Cl2 = 35.453g*2 = 70.906g 2H2 = 1.00794g*4 = 4.03176g 2O = 15.9994g*2 = 31.9988g 40.078g + 70.906g + 4.03176g + 31.9988g = 147.01456g or 147.0 g CaCl2 1g CaCl2 * 2H2O x (1 mol CaCl2 *2H2O/147g CaCl2 *2H2O) = 0.0068 mol of CaCl2*2H2O Molar mass was then
Premium Stoichiometry