Which of the following describes what a scientist does

Which real-world scenarios below represent physical and chemical changes? -running a car -exploding fireworks -mixing water and powdered drink mix -combining oil and vinegar to make salad dressing -taking aspirin for a headache -diluting bleach with water-digesting dinner-spreading peanut butter on bread

Asolution contains 180 g of glucose (c6h12o6) and 162 g of water. what is the mole fraction of glucose?

How many moles of cu are needed to react with 5.8 moles of agno3? cu + 2 agno3 → cu(no3)2 + 2 ag