What do 7-11 year olds know about pH?

[lucyellensmum]

I have to help at a science day in a school this week. This will be my first venture back into the real world of work and im helping my old supervisor with a presentation on pH, with the help of some ants and litmus paper. My chemistry is rusty to say the least - I was told that they really wont know very much, just to talk about acid, and base etc. We are going to be testing the pH of various household liquids from lemon juice to oven cleaner (diluted!).

What on earth are you going to do with the ants? Squoosh them for the formic acid?

Year 3s seem to know vinegar is acid and baking soda is alkali. Well - thats the extent of dds knowledge though we did have a play when I made some litmus solution accidently purple sprouting broccoli (made a blue soup by accident lol!)

absolutely nothing in many cases
start at zero and they'll pick it up pretty quick.
good luck!

ds(yr5) has done some very basic ph testing of substances with coloured liquids

lol kitten, no ants will be harmed during the experiments! Which means i mustnt let them all escape like i did the other day and have to stamp on them! What we are going to do is, aneathetise them with some dry ice and pick them up with some cocktail sticks and vaseline and get them to squirt it onto the litmus paper - yeah, its as tricky as it sounds .

We are going to tell them about the home made indicator, except we are goint to suggest red cabbage.

wow - that sounds amazing!
oh for a source of dry ice.....

they probably don't know anything about pH as such, but they might have dabbled with red cabbage indicator.

Make sure they wear safety glasses when they are doing their testing

lol at the dry ice. I think the university biology department feels the same, considering how long it took us to ponce some the other day . It must be in short supply, when i was a student we used to turn the labs into discos with it [when the supervisors had gone home of course'

We do red cabbage indicator in year 7 if that's any use.
Hope you are doing the pH of cola too - that's always a good one

yes, coke, lemon juice, toothpaste, oven cleaner, cant remember what else we had. oh, baking powder. I just hopwe i have more sucsess with my ants on the day - have a tendancy to squash them

kids love goggles !
I took a load of H&S stuff into DSs primary school & did a talk - they all loved the dressing up bit in gloves, goggles, hard hats etc

we are giving them latex gloves to wear, not because its dangerous at all, but it will make them feel like scientists. Im really excited

/sniggers at poor squashed rather confused ants...

Head and Shoulders shampoo has a pH of 8-9 and if you heat it up you could perm your hair with it -nasty stuff dont wash your hair with it.

thanks for that ivy . I have often had to keep a supply of that for when DD has dyed her hair and decides she doesn't like the colour - strips it stright out!

So, we did it, it was great fun, the kids loved it and were really enthusiastic about it. No difficult questions thankfully. Definately given me something to think about re teaching