For all three questions, we will use the fact that
- molarity = (moles of solute)/(liters of solution)
1) For 175 mL of solution at 0.203 M, this means that:
- 0.203 = (moles of solute)/0.175
- moles of solute = 0.035523 mol
Considering the hydrochloric acid solution, if we have 0.035523 mol, then:
- 6.00 = 0.035523/(liters of solution)
- liters of solution = 0.035523/6.00 = 0.0059205 = <u>5.92 mL (to 3 sf)</u>
<u />
2) If there is 20.3 mL = 0.0203 L, then:
- 8.20 = (moles of solute)/0.0203
- moles of solute = 0.16646 mol
This means that the molarity of the diluted solution is:
- 0.16646/(0.200) = <u>0.832 M (to 3 sf)</u>
<u />
3) If we need 1.50 L of 0.700 M solution, then:
- 0.700 = (moles of solute)/1.50
- moles of solute = 1.05 mol
Considering the 9.36 M acid solution, from which we need 1.05 mol of perchloric acid from,
- 9.36 = 1.05/(liters of solution)
- liters of solution = 1.05/9.36, which is 0.11217948717949 L, or <u>112 mL (to 3 sf)</u>
Radioactivity comes from unstable atoms of certain elements. Radioactivity consists of alpha radiation (2 protons and 2 neutrons), beta radiation (1 electron), or gamma radiation (Electromagnetic photons).
<u>Given:</u>
Mass of pure iron (Fe) = 3.4 g
<u>To determine:</u>
Mass of HBr needed to dissolve the above iron
<u>Explanation:</u>
Reaction between HBr and Fe is
Fe + 2HBr → FeBr₂ + H₂
Based on the reaction stoichiometry-
1 mole of Fe reacts with 2 moles of HBr
# moles of Fe = mass of Fe/atomic mass of Fe = 3.4/56 g.mol⁻¹ = 0.0607 moles
Therefore # moles of HBr = 2*0.0607 = 0.1214 moles
Molar mass of HBr = 81 g/mole
Mass of HBr = 0.1214 moles * 81 g/mole = 9.83 g
Ans: Mass of HBR required is 9.83 g
Answer:i read it Explanation:
