How many moles of tungsten atoms are in 4.8 × 1023 atoms of tungsten?

-  0.80 moles

Solution:- Number of atoms of tungsten are given and we are asked to calculate the moles of tungsten atoms. So, it is a atom to mole conversion and for this we use the Avogadro number.

Number of atoms are divided by Avogadro number to get the number of moles.

Avogadro number is . Given number of atoms is . let's divide it by Avogadro number.

Numerator and denominator has equal exponent so it is canceled. So, we only need to divide 4.8 by 6.022 and round the answer to two sig figs as given number of atoms has only two sig figs.

= 0.80 moles

Hence, there are 0.80 moles of tungsten atoms in given number of atoms.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.