hope this helps
1 OH- plus H+ = HOH or H2O One mole of OH- combines with one mole of H+ to make one mole of water. therefore .50 moles of OH- will combine with .50 moles of H+ to make .50 moles of H2O and the solution will be neutral with a pH of 7.
2. Balance the equation first. 2 HCl + Mg = MgCl2 plus H2(g)
Now get the l0 grams of Mg into moles. l0 grams Mg over 24 grams Mg/mole = .417 moles Mg
Now notice in the balanced equation that 2 moles of HCl reacts with one mole of Mg, therefore we need two times as many moles of HCl as we have of Mg.
2 times .417 moles Mg = .833 moles HCl needed
In any solution Moles solute = Molarity times volume in LITERS
switching this around Volume in Liters = Moles solute over Molarity
Volume HCl needed = .833 moles HCl over 7.0 Molar HCl = .119 Liters or 119 ml
3. Reaction balanced 2 Fe + 6HCl = 2 FeCl3 + 3 H2
Get the 450 grams of iron into moles first. 450 gms Fe over 56 grams Fe per mole = 8.04 moles Fe
Now use the balanced equation as a math platform. Write out the equation on a ;piece of paper.
Over the 2Fe enter 8.04 moles and below the same enter its coefficient of 2 moles
Now over the 6HCl enter X moles and below the same enter its coefficient of 6
Now cross multiply through the equation and solve for X moles of HCl I got 24.1 moles of HCl needed.
Moles HCl = Molarity times Volume in Liters
Volume in liters = Moles HCl over Molarity which = 24.1 moles HCl over 14.0 Molar HCl acid
which = 1.72 Liters HCl acid or 1720 ml. If if the pen held 5 ml of acid, it would have to be refilled about 344 times. No way this would fit into the pen.
What minimum volume of 14.0 M hydrochloric acid would be required to completely dissolve a 600.0 −g iron bar?
I'm getting around 2.3 L but it's saying it's incorrect...
2 answers
The work done by Nick is interesting but it doesn't answer the question.
Fe + 2HCl ==> FeCl2 + H2
mols Fe = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols Fe to mols HCl. That's mols HCl = twice mols Fe.
Now convert mols HCl to volume.
M HCl = mols HCl/L HCl.
You know M HCl and mols HCl, solve for L HCl. Convert to mL if desired. 2.3 L is way too large by a factor like 2000 time too large.
Fe + 2HCl ==> FeCl2 + H2
mols Fe = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols Fe to mols HCl. That's mols HCl = twice mols Fe.
Now convert mols HCl to volume.
M HCl = mols HCl/L HCl.
You know M HCl and mols HCl, solve for L HCl. Convert to mL if desired. 2.3 L is way too large by a factor like 2000 time too large.
1 answer