The anwser is atoms are destroyed
Answer:
Mass: 981.0 g
Density: 5.61 g/cm^3
Hardness: = 2.5 - 3
Unknown material: Chalcocite
Answer:
3.56x10^24 molecules
Explanation:
The following data were obtained from the question:
Mass of Na2SO4 = 840g
Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.
If 1 mole (i.e 142g) contains 6.02x10^23 molecules,
Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules
NaOH +HCl ---> NaCl +H2O
n (mol HCl) = n (mol NaOH)
M- molarity
V - volume
M(HCl)V(HCl) = M(NaOH)V(NaOH)
M(HCl)= M(NaOH)V(NaOH)/V(HCl)
M(HCl)= 10⁻³*25.3 ml/5.25 ml=<span>4.82 × 10⁻³ M molarity HCl</span>
