How many molecules are in 23 moles of oxygen? I will give brainlist (ion remember what is called) to the person who actually shows the steps

Cucl2 + 2nano3 cu(no3)2 + 2nacl what is the percent yield of nacl if 31.0 g of cucl2 reacts with excess nano3 to produce 21.2 g of nacl? 49.7% 58.4% 63.6% 78.7%

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *

How many moles of potassium hydroxide are needed to completely react with 2.94 moles of aluminum sulfate