Chemistry, 10.01.2020 07:31, montgomerykarloxc24x

Hard water often contains dissolved ca2+ and mg2+ ions. one way to soften water is to add phosphates. the phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. suppose that a solution is 5.5×10−2m in calcium chloride and 9.5×10−2m in magnesium nitrate.

what mass of sodium phosphate must be added to 2.0l of this solution to completely eliminate the hard water ions? assume complete reaction.

Answers: 2

Show answers

Answers

Ok so, Im going to try to explain this: What we need to do we are going to do this on 3 steps: 1) We need to get the total of moles of calcium + magnesium. 2) Multiply it by 2/3 to get the moles of phosphate 3) from there we need to get the grams of sodium phosphate. So we need those three operations like this:

Moles calcium = 5.5 x 10^-2 moles/liter x 2 liters = 11.0 x 10^-2 moles
Moles magnesium = 9.5 x 10^-2 moles/liter x 2 liters = 19.0 x 10^-2 moles
Total moles of Ca + Mg = 11.0 x 10^-2 + 19.0 x 10^-2 = 30.0 x 10^-2 moles.

Then we include the grams of Na3PO4 that is 163.9408 g/mol and finally you do this operation 163.9408 g/mol x 20.0 x 10^-2 moles = 32.8 grams = 33 grams. And that is how you get it

answered: Guest

assuming that your periodic table has eighteen columns, you should highlight the four elements in the third column from the left of the table.

explanation

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the $3d$ have energy higher than those in the $4 s$ orbital while lower than those of the $4 p$ orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the $4s$ orbital is therefore filled right after $3p$ orbitals and before $3 d$ orbitals.

potassium has electron configuration $[\text{ar}] 4 s^{1}$ and calcium $[\text{ar}] 4 s^{2}$ . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration $[\text{ar}] 4 s^{2} \; 3d^{1}$ and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the $ns^{2} \; (n-1) p^{1}$ and should be highlighted as well.

answered: Guest

un recipient conține 6,4 moli de gaz. gazul hidrogen reprezintă 25% din totalul kilometrilor din container. în cazul în care presiunea totală este de 1.24 atm ceea ce este

Other questions on the subject: Chemistry

Chemistry, 22.06.2019 16:30, jrfranckowiak

At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?

Answers: 1

continue

Chemistry, 22.06.2019 19:30, kenoknox

Astudent conducts an experiment to determine how the amount of water given to a plant affects its growth. what is the independent variable for this experiment?

Answers: 1

continue

Chemistry, 22.06.2019 20:30, hsbhxsb

We are hoping to create 5.72 grams of glucose. the plant was given 4.75 liters of co2 and 2.81 g of h20. which reactant was the limiting reagent? how much excess mass did we have of the other reactant?

Answers: 3

continue

Chemistry, 22.06.2019 20:40, ohgeezy

Select the correct value for the indicated bond angle in each of the compounds. o−o−oo−o−o angle of o3 90° 109.5° < 109.5° 120° < 120° 180° f−b−ff−b−f angle of bf3 180° < 109.5° < 120° 120° 109.5° 90° f−o−ff−o−f angle of of2 < 120° 120° 90° 109.5° 180° < 109.5° cl−be−clcl−be−cl angle of becl2 90° 109.5° 180° 120° < 109.5° < 120° f−p−ff−p−f angle of pf3 90° 109.5° < 109.5° 180° 120° < 120° h−c−hh−c−h angle of ch4 90° < 109.5° 180° 120° < 120° 109.5°

Answers: 1

continue

Do you know the correct answer?

Hard water often contains dissolved ca2+ and mg2+ ions. one way to soften water is to add phosphates...