Why must sample spots be above the solvent in paper chromatography

7.) A syringe initially holds a sample of gas with a volume of 285 mL at 355 K and 1.88 atm. To what temperature must the gas in the syringe be heated/cooled in order to have a volume of 435 mL at 2.

How is enthalpy used to predict whether a reaction is endothermic or exothermic? A) When the enthalpy of the reactants is higher than the enthalpy of the products, the reaction is endothermic.

At what time of day are dissolved oxygen levels most likely to be highest? A. 6:00 AM B. 12:00 PM (noon) C. 6:00 PM D. 12:00 AM (midnight)

Number of parents who contribute genetic information to the offspring in pink salmon?

When performing your experiment, you add your first drop of oleic acid/benzene solution, and a lens forms immediately. what is wrong with your setup, and how can it be corrected?

Explain Charles law

2 H2 + O2 → 2 H2O What is the product of this chemical reaction

Which of the following is a chemical property? A.) Ability to burn B.) Mass C.) Density D.) All of the above

What is the density of rock if it has a mass of 25 g?

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction.