Answer:
33.33% = 33%
Explanation:
MgCO3(s) + 2HCl (aq) --> MgCl2(aq) + H20(l) + CO2(g)
1 mole of MCO3 will produce → 1 mole of CO2
We need to get the number of mole of CO2:
and when we have 0.22 g of CO2, so number of mole = mass / molar mass
Moles = 0.22 g / 44 g/mol = 0.005 mole
Moles of Mg = moles of CO2 = 0.005 mole
Mass of Mg = moles * molar mass
= 0.005 * 84 /mol = 0.42 g
Percent of MgCO3 by mass of Mg = 0.42 g / 1.26 * 100
=33.33 %
Answer:
Copper
Explanation:
copper is used in the wiring of the phone
Valence electrons are located in the outermost shell of the atom.
PH measures the concentration of hydrogen ions on the log 10 scale. Thus, a pH 5 solution has 2 order of magnitude difference from that of pure water, which has a pH of 7.
Therefore,

. A solution of pH 5 has 100 times more hydrogen ions that that of pure water.