Download presentation

Presentation is loading. Please wait.

Published byJanice Philomena Booth Modified over 8 years ago

1
Making Molar Solutions From Solids

2
What are molar solutions? A molar solution is one that expresses “concentration” in moles per volume Usually the units are in mol/L mol/L can be abbreviated as M or [ ]

3
Calculations with molar solutions Q: How many moles of NaOH (s) are required to make 7.5 L of a 0.10 M solution? M=n/L, n = 0.10 M x 7.5 L = 0.75 mol # mol NaOH= 7.5 Lx 0.10 mol NaOH 1 L = 0.75 mol

4
DO this INDIVIDUALLY!! You are given provided with solid NaCl. Describe (in writing) how you can prepare 100 ml of a salt solution of 0.10 M NaCl in this lab. How much NaCl do you need? Bring up your work to the front. Preparing molar solutions from solids – LAB TIME!

5
Equations using moles n = N N A n = m MM n = C x V

6
Molar solutions are prepared using: -a balance to weigh grams -a volumetric flask to measure litres L refers to entire volume, not water! Because the units are mol/L, we can use the equation M = n/L Preparing molar solutions from solids

7
Practice making molar solutions 1.Calculate # of grams required to make 100 mL of a 0.10 M solution of NaCl. Do this part individually. 2.Get 250 mL volumetric flask, squirt bottle. Rinse all with tap water. 3.Pour a little (20 - 30 mL) distilled H 2 O into flask. 4.Weigh NaCl. Add it to flask. 5.Mix (by swirling) until the NaCl is dissolved. 6.Add distilled H 2 O to the 100 mL line.. 7.Rinse & return equipment.

8
Calculating grams of NaCl Molarity of solution = 0.5 M NaCl Volume solution = 100 ml = 0.1 L M = n/V n = MxV = 0.5M x 0.1L = 0.05 moles NaCl MM = m/n m = MMxn = 58.44g/molx0.05mol = 2.9 g NaCl

9
Practice Unit conversion Do above question using unit conversion Page 290. Do Q 19 - 22 Do all these questions using unit conversion For any test/quiz, you can use either Unit conversion OR equations.

Similar presentations

© 2024 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google