Bit confused about this question. especially a and b. Not really sure which values to use or how.
Thanks!
A solution is made by dissolving 1.71g of barium hydroxide, Ba(OH)2 (s), in distilled water and then adding more distilled water until the total volume of the solution is one litre (1.00dm3). Calculate:
(a)the molarity of the barium hydroxide solution
(b)the hydroxide concentration in mol dm^-3
(c)the pOH of the solution
(d)the pH of the solution
a. molarity is defined as # moles/L solution. To find # moles, grams/molar mass.
b. Look at the formula. There are two OH ions per Ba(OH)2 molecules; therefore, the concn of OH must be twice the answer to a.
c. pOH = -log(OH). You have the OH from part b.
d. pH + pOH = 14. You have pOH from c, the only unknown is pH.
Post your work if you get stuck.
No problem! Let's break down the steps to calculate each of these values:
(a) To find the molarity of the barium hydroxide solution, you need to know the number of moles of barium hydroxide, Ba(OH)2, in the 1.00 dm^3 solution.
First, calculate the number of moles of Ba(OH)2 by dividing the mass of the compound (1.71g) by its molar mass. The molar mass of Ba(OH)2 can be calculated by adding up the atomic masses of barium (Ba), oxygen (O), and hydrogen (H) in the formula.
Once you have the number of moles of Ba(OH)2, divide it by the total volume of the solution in liters (1.00 dm^3) to get the molarity, which is moles per liter (mol/L).
(b) To determine the hydroxide concentration in mol dm^-3, you need to know the ratio of hydroxide ion (OH-) to barium hydroxide (Ba(OH)2) in the solution. Since there are two OH- ions for every Ba(OH)2 unit, you can multiply the molarity of the barium hydroxide solution (from part (a)) by 2 to obtain the hydroxide concentration in mol dm^-3.
(c) To calculate the pOH of the solution, you can use the equation pOH = -log[OH-]. First, determine the concentration of hydroxide ions (from part (b)). Take the negative logarithm (base 10) of the concentration to obtain the pOH value.
(d) Finally, to find the pH of the solution, you can use the equation pH + pOH = 14. Since you have already calculated the pOH (from part (c)), subtract it from 14 to obtain the pH of the solution.
By following these steps, you should be able to determine the values for each part of the question. Remember to use the correct formula, convert units if necessary, and check your calculations to ensure accurate results.