Which of the following is a chemical reaction?

1 - Dropping a sliced orange into a vat of Sodium Dydroxide

2-Cutting a piece of paper into two pieces

3-Filling a balloon with air

4-Freezing liquid Mercury

A 1.50L buffer solution is 0.250 M in HF and 0.250 in NaF. Calculate the ph of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of the base. The Ka for HF is 3.5E^-4

What are the two changes in matters

Discuss how electric cureent is able to flow

Consider the reaction 2CuCl2 + 4KI → 2CuI + 4KCl + I2. If 4 moles of CuCl2 react with 4 moles of KI, what is the limiting reactant? CuCl2 KI CuI I2

For a reaction where h is negative and s is negative, the reaction will be

How many hydrogen atoms are in 2.80 mol of ammonium sulfide?

What is a large oval structure that directs all of the cells activities?

HBr + H₂SO₄ SO₂ + Br₂ + H₂O What is the oxidation number of the oxidizing agent? What is the oxidation number of the reducing agent?

How do find the volume of 60.0g of ether if the density is. 70g/mL?

A population of crabs live on a light-colored sandy beach. In this environment there is a population of birds that eat the crabs. One year, there is a volcanic eruption near the beach and dark volcanic ash covers the beach.