Download presentation

1
Ch 13 Solutions Sec 2 pg 467 #1-11

2
**1. Why did chemists develop the concept of molarity?**

To easily connect the amount in moles of a substance with its concentration in a solution

3
**2. In what units is molarity expressed**

Moles per liter Mol/L

4
**3. Describe in your own words how to prepare 100. 0 mL of a 0**

3. Describe in your own words how to prepare mL of a 0.85 M solution of sodium chloride. 23Na + 36Cl= 59NaCl .85 mol NaCl x 59 g/mol = 50 g/L or 5.0g NaCl for 1/10 L (100ml) Weigh 5.0 g of salt, dissolve in water. Pour into 100 ml volumetric flask, swirl and fill to volumetric line

5
**4. If you dissolve 2. 00 mol KI in 1. 00 L of water, will you get 2**

4. If you dissolve 2.00 mol KI in 1.00 L of water, will you get 2.00 M solution? Explain. No The total volume may be different by the time the solute is dissolved.

6
**5. A sample of 400. 0 g of water is found to contain 175 mg Cd**

5. A sample of g of water is found to contain 175 mg Cd. What is this concentration in parts per million. Change mg to g 175 mg x 1 g/ 1000 mg = .175 g Cd Find g Cd/g of water .175 g/ g water x 1000,000 parts /1 million = or parts per million or ppm

7
**1.63 parts per million or ppm He**

6. If 1.63 x 10-4 g of helium dissolves in g of water, what is the concentration in parts per million? How much in 1 gram of water? 1.63 x 10-4 g He / 100g H2O x 1000,000 parts/million 1.63 parts per million or ppm He

8
**A standard solution of NaOH is 1. 000 M**

A standard solution of NaOH is M. What mass of NaOH is present in mL of the solution? Na = 23, O = 16, H = 1 NaOH = 40 40 g in 1 M 100 mL is 1/10 L so 40/10 = 4 g in mL

9
8. A 32 g sample of LiCl is dissolved in water to to form 655 mL of solution. What is the molarity of the solution? Convert mass to moles. Li = 6.9,Cl = 36 32 g x mol/43g LiCl = .74 mol LiCl Convert mL to L 655 ml x 1 L/ 1000mL = .655 L Find Moles per Liter .74 mol / .655 L = or M LiCl

10
**9. Most household bleach contains sodium hypochlorite, NaOCl. A 2**

9. Most household bleach contains sodium hypochlorite, NaOCl. A 2.84 L bottle contains 177 g NaOCl. What is the molarity of the solution. Find moles of NaOCl Na=23,O=16,Cl=35.5 177g NaOCl x mol/74.5g NaOCl = 2.38 Mol NaOCl Find mol/L 2.38 mol/2.84 L = or mol/L or M

11
**10. What mass of AgNO3 is needed to prepare 250. 0 mL of a 0**

10. What mass of AgNO3 is needed to prepare mL of a M solution. Ag=108,N=14,O3= 16(3)= 48 AgNO3 = 170 g M = g/L = 170g /mol = for 1 Mol solution 170/4 for .250 L = 42.5 g for .250 L AgNO3 42.5 g for 1 M, 42.5 x .125 M 5.25 or 5.3 g AgNO3 for .125 M solution

12
11. Calcium phosphate used in fertilizers can be made in the reaction described by the following equation: 2H3PO4(aq) + 3Ca(OH)2(aq) --> Ca3(PO4)2(s) + 6H2O(aq) Ca=40(3), P=31(2), O=16(8)=128, = 310g total H= 1(2), O=16, total 18g total What mass in grams of each product would be formed if 7.5 L of 5.00 M phosphoric acid reacted with an excess of calcium hydroxide? H3PO4 = 1(3) (4) or 64 = 98g for 1 M 98x5 x 7.5 = 3,562.5 or g H3PO4 3600g 2H3PO4 x 1 mol/98g x 1 mol Ca3(PO4)2 /2mol 2H3PO4 x310 g Ca3(PO4)2 /1 mol Ca3(PO4)2 = 5,693.8 or 5.7 x 103 Ca3(PO4)2 18g H2O

Similar presentations

Presentation is loading. Please wait....

OK

Metal + Acid Displacement. Activity Series of Metals.

Metal + Acid Displacement. Activity Series of Metals.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Free ppt on save environment Ppt on business etiquettes training day cast Free ppt on law of demand Download ppt on changes around us Ppt on marie curie's accomplishments Ppt on building information modeling degree Ppt on understanding marketing management Ppt on endangered and endemic species in india Ppt on buddhism and jainism pictures Ppt on mirror link