rob qu bo otslogos S1 9 re o m onolqmo ber 5. What is the safety precaution associated with heating the reaction mixture? gne ot l eimiqioong to iiinup bno stutxinn TO 19 erb lo 1oloo edi W o nielaxd Sn o euT Sd p sdrbadn amd ho v AX 891 ri to 916 Name Section Using class data, plot the mass of precipitate on the ordinate and the amount in millimoles of 0.100 M Pb(NO3)2 on the abscissa. Select the scale units on the ordinate to range from 0 to 0.1 g more than the maximum mass of precipitate reported. Select the scale units for the abscissa to range from 0 to 2.00 mmol of Pb(NO))2. Draw the best straight-line curve through the plotted points on the left-hand side of the graph. Draw a second best straight-line curve through the plotted points on the right-hand side of the graph. The point of intersection of the two straight lines is the stoichiometric point for the system. This point represents the number of millimoles of Pb(NO3)2 that react with 1.20 mmol of K2CrO4. CALCULATIONS AND QUESTIONS 1. Based on the stoichiometric point found on the graph of the class data, determine the mole ratio of K2CRO4 to Pb(NO3)2. [mmoles K2CrOa/ mmoles Pb(NO3)2] 2. The precipitate contains lead and chromate ions. Identify the chemical formula of the precipitate. 3. Write the balanced chemical equation for the reaction between K2CrO4 and Pb(NO3)2. 4. Determine the number of millimoles (mmol) of each reactant present when 3.00 mL of 0.100 M Pb(NO3)2 is mixed with 12.00 mL of 0.100 M K2CrO4. Sd aried Haeup's mus of tpe byxoec.dao arcı able The limiting reagent is the reactant that is completely used up during a chemical reaction. The other reactant is said to be in excess. After the reaction has reached completion, some of the excess reactant remains unreacted. Which reactant is the limiting reagent and which is in excess for the above experimental conditions? Rordoss 5. What trend do you observe for the color of the reaction mixture and quantity of precipitate for the reactions prior to the stoichiometric point? Explain your answer. What trend do you observe for the color of the reaction mixture and the quantity of the precipitate 1or e reactions after the stoichiometric point? Explain your answer.