</span>Molarity is a measure of the concentration of solute in a solution. It can be expressed as moles of solute ÷ volume of solution: c = n ÷V where: c - concentration of solute, n - moles of solute V - volume of solution <span> We have: c = 3 M V = 75 ml = 0.075 l n = ? Any gas at STP occupies 22.4 l/mol.</span><span>
If </span><span>c = n ÷V, then n = c </span>× V n = 3 M × 0.075 l n = 0.225 moles HCl
In the reaction, there are 2 moles of HCl, so moles of H₂ would be the half of HCl moles: n₁ = 0.255 moles HCl ÷ 2 n₁ = 0.1275 moles <span>H₂ </span> Thus, if n₁ = 0.1275 moles H₂, and Mg<span> at STP occupies 22.4 l/mol</span><span>, then </span>0.1275 moles H₂ × 22.4 l/mol = 2.52 l
The magnetic field is believed to be generated by electric currents in the conductive material of its core, created by convection currents due to heat escaping from the core. So your answer is A
