A solid with a mass of Mgrams is melted by heating it. After a half-hour, the solid is fully converted into liquid. What will be the mass of the liquid obtained during the
process?
equal to M
equal to 2M
less than M
more than M
PLEASE HELP

equal to M

Explanation:

The mass of the fully melted mass and the initial solid will be the same. So, the mass of the melt is equal to M.

Mass is the amount of matter contained within a substance. Since only the phase changed and the amount of matter is still the same, the mass of the molten phase and the solid phase will remain the same.

We are correct to say that in the heating process no mass was destroyed or added in melting the solid.

A simple phase change that preserved the mass only occurred.

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.