Question: how many moles of rice grains are equal to 1.807?
Answer: In this problem,it is very important to use the constant called Avogradro's number which is equal to 6.022 * 10^23 particles per mole. For any kind of substance, whatever it is, this is the number of particles that constitute 1 mole. This means that 6.022x10^23 grains is equivalent to 1 mole of rice grain.