Q5. A scientist is studying the reactions of the Group 1 and Group 2 elements. A First, the scientist compares how quickly the Group 1 elements react.
He adds some lithium to water. At the same time, he starts a stopwatch.
He measures the time taken for the bubbles to stop. He does the same for some other Group 1 elements.

I State one safety precaution the scientist should take, apart from wearing eye protection, when conducting the reactions of the group 1 metals.

(1 mark) ii Suggest two things the scientist could do to make the test fair. (1 mark) iii The scientist records their results in a table. In the table, the elements are listed in the same order as they are in the periodic table
. Element Time for bubbles to stop (s) lithium 122 sodium 80 potassium 61 Describe the pattern in the results, going down Group 1 from lithium to potassium.
(1 mark) b Next, the scientist adds some Group 2 elements to water. He writes his results in a table. In the table, the elements are listed in the same order as they are in the Periodic Table. Group 2 element Observations when added to cold water magnesium small bubbles form on surface of magnesium calcium bubbles vigorously strontium barium bubbles extremely vigorously i Predict what he will observe when he adds strontium to water. (1 mark) ii Give a reason for your prediction. (1 mark) Maximum 5 marks

Activity two: just lemons, inc. production here's a one-batch sample of just lemons lemonade production. determine the percent yield and amount of leftover ingredients for lemonade production and place your answers in the data chart. hint: complete stoichiometry calculations for each ingredient to determine the theoretical yield. complete a limiting reactant-to-excess reactant calculation for both excess ingredients. water sugar lemon juice lemonade percent yield leftover ingredients 946.36 g 196.86 g 193.37 g 2050.25 g 89% just lemons lemonade recipe equation: 2 water + sugar + lemon juice = 4 lemonade mole conversion factors: 1 mole of water = 1 cup = 236.59 g 1 mole of sugar = 1 cup = 225 g 1 mole of lemon juice = 1 cup = 257.83 g 1 mole of lemonade = 1 cup = 719.42 g show your calculations below. analysis questions 1. based on taste observations only, which ingredients were in excess in the lemonade samples in activity one? in activity one the excess substances for each sample were the water and sugar. 2. based on the data in activity two, which excess ingredients are affecting the taste of the lemonade in the sample batch? 3. what can just lemons, inc. do during production to reduce the amount of excess ingredients and improve the taste of their lemonade? 4. try to reduce the amount of leftover ingredients by changing the amount of one, two, or all three starting ingredients. show your stoichiometric calculations below. 5. during factory inspection, just lemons, inc. discovered that a water valve to the lemonade mixing station was not functioning. once they repair it, more water will enter the mixing station. from what you know about the limiting and excess ingredients for current lemonade production, what advice would you give engineers about the upcoming increase in water?

Amixture with the same composition throughout is!

How are evaporation and sublimation similar? a both involve the formation of a gas. b both release energy to the surroundings. c both take place throughout a solid. d both take place at the surface of a liquid.