Water
hydrogen ions+hydroxide=water
which can be verified by dark reaction of photosynthesis
answer
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle
Eric can make the hypothesis that the batteries died
The molarity of HCl is calculated as below
find the moles of mg used
moles = mass /molar mass
= 2.00g/24 g/mol=0.083 moles
write the reacting equation
Mg(s) +2HCl (aq)= MgCl2(aq) + H2(g)
by use of mole ratio between Mg to HCl which is 1 :2 the moles of HCl is therefore
= 0.083 x2 =0.166 moles
molarity of HCl = moles of HCl/ volume in dm^3
that is 0.166/50 x1000= 3.3 M of HCl