can someone help me on these questions Example: How many milliliters of s.5 M Na

Question

can someone help me on these questions

Example: How many milliliters of s.5 M NaDH are needed to prepare 300 m l. of 1.2 M NaOH? x 300 mL SS Mxvi “ 1.2 300mL 5.5 M “1.23, x -65mL So. so prepare the 1.2 M NaOlf solution, you pour 65 mL, of 5.5 M NaOH into your container and add water to get 300 mL final volume Practice Problems: is the molarity of sodium hydroxide, NaOH, in a solution prepared by dissolving 250 g of NaOH in enough pare water to make 1500 mL of solution 2. What is the What is the 3. 4s0 g of sodium bromide, NaB, is used to prepure 1250 ml. of solution. molarity of NaBe in this solution? 4. How many moles of NaCl are in 875 ml of a 0.250 M sodium chloride solution? 5. How many milliliters of 0.750 M NaOH would contain exactly 5.00 g of Na01H? 6. Hydrochloric acid is purchased as a 12.1 M solution. How many milliliters of 12.1 M hydrochloric acid must be diluted with water to prepare 2.00 L. of 0.200 M acid? 7. How many milliliters of 10.0 M sodium hydroxide must be used to prepare 500 ml. of 0.100 M NaOH solution? 8. What volume of 4.75 M copper salfitte, Cus04, must be used to prepare 5.00 L of 0.250 M copper sulfate solution? 9. How many grams of nickel (II) chloride hexahydrate are required to prepare 250 mL of aqueous solution whose concentration is 0.255 M? 10. An agricultural chemist wished to studly the effect of varying fertilizer applications on the growth of tomato plants. The chemist prepared a "stock" aqueous solution of urea, (NH2 CO, by dissolving 1.75 g of this compound in water to make 1.00 L of solution. Then she prepared a series of more dilute solutions to apply these solutions contained 5.00 mL of "stock" solution diluted to give a final volume of 25.00 mL. What was the concentration of urea in this diluted solution? to her tomato plants. One of

Explanation / Answer

Q1.molarity=no. of moles of solute//volume of the solution.

M=(nb/Vs)*1000 {multiply by 1000 if volume of solution is in ML to convert it into litre)

nb=no. of moles of solute

Vs=volume of the solution

a= used on base for solvent

b=used for solute

Molecular mass of NAOH=40

Vs=1500 ml

Wb=25gm

M=(25/40*1500)1000=.41M

Q2.M=(.155/350)1000=.44M

Q3.Mb of NaBr=102.90

M=45/102.90*1250)*1000=.349M

Q4..250=nb/875)1000

nb= .21 moles

Q5..750=5/40*v

V=6L=6000ML

Q6.NO. of moles is always constant for solution

M1*V1=M2*V2

12.1*V1=2*.200

V1=.033 L

Q7.VS=0.5*.100)/10=.005L

Q8.VOLUME OF SULPHATE=5*.250)10=.125L

Q9..255=Wb*1000)/237.68*250

Wb=15.15gm.

Q10.molecular weight of urea=60

1.75*1)/60*1=M2*25)1000=1.166L

M=1.166L

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.