Can someone please help me. Like I don’t know if it’s a physical change or chemical change. Is it a physical or chemical change and why is it that change.

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

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?

List a abiotic factors and character