Barium Hydroxide - urgent!

[merilyn]

I'm trying to make up 250mL of 0.1M Barium Hydroxide by 11am. The MW on the bottle is 315.47. So I can check my calculations, can someone tell me how much I should have used?
It's taking a long time to dissolve, I've put it on the stirrer, then tried some heat but it's still looking like it's not going to dissolve.

[smiley]

You should be dissolving 7.88g in 250mL. Hope that helps.

[merilyn]

Thanks, Smiley, at least I know my maths is right! I didn't want to say it up front in case I'd had a "moment" and completely forgotten all the basics of algebra! Thanks for being braver than me!!