No. of moles = mass / molar mass
= 100/35.5
The number of atoms of K that are in 235 g of the compound is
2.57 x10^24 atoms
calculation
Step 1: find the moles of K2S
= moles = mass/molar mass
= 235 g/110 g/mol= 2.136 moles
Step 2: multiply 2.136 moles by no. of K atoms in K2S
= 2.136 x2 = 4.272 moles
Step 3: use the Avogadro's law to determine number of K atoms
that is according to Avogadro's law 1 mole = 6.02 x 10^23 atoms
4.272 moles= ? atoms
by cross multiplication
= (4.272 moles x 6.02 x10^23 atoms) / 1 mole = 2.57 x10^24 atoms
Answer:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic.
Explanation:
<span>The normal dividing line for soluble/not soluble is 0.1 M.
If a substance, as a saturated solution at room temp and pressure, cannot form a solution concentration of 0.1 M, then it is considered insoluble.
The 0.1 M figure was selected because _most_ substances are either well above that value or well below. Some substances (calcium hydroxide is one? not sure) come close to the 0.1 M dividing line but there are only a very few.</span><span>
but most likely it wont mix</span>
