Calcium Metal and HCl

[Wayne]

A grade 10 class is doing reactivity of metals and are using the usual metals in HCl. The teacher is wanting to demo calcium in 2M HCl. It's been a very long time since I have used Ca, and for the life of me can't remember if it safe to add it HCl or the reaction is too violent.
Did a quick search on here but couldn't find an answer. Hoping someone out there can help me.

[macca]

Hi Wayne

the CSIS manual says "Used to compare the reactivities of metals, with water, air,dilute acids."

but also says Evolves flammable hydrogen gas on contact with water; hydrogen and air will explode if ignited.

[mtg]

Try a grain first, if you have really good calcium it will probably be EXTREMELY reactive in water and HCl. As ours is ancient we use a glass rod to take the oxidization off, a couple of grains with water is ample and reacts well ( H collected in an inverted Test Tube and subjected to the pop test)so I assume the HCl will also.

[sunray18]

We use it in water - this is violent enough

[mtg]

Yes agreed, but maybe a 0.1M HCl will prove the point. Or set up a quikfit, with calcium in the bottom and a bit of dilute acid in a separating funnel with tubing off the middle-joining-bit (the name of which I cant remember) and bubble it up thru' a beehive (in a trough of water, in a fume hood), and displace water out of a gas jar.Will prove reactive properties after the very dilute soln has proved the Hydrogen.

[Wayne]

Thanks guys! It confirms what I thought, use just water, but as my brain was failing me yesterday wanted to ask and make sure.

[Wayne]

Yes agreed, but maybe a 0.1M HCl will prove the point. Or set up a quikfit, with calcium in the bottom and a bit of dilute acid in a separating funnel with tubing off the middle-joining-bit (the name of which I cant remember) and bubble it up thru' a beehive (in a trough of water, in a fume hood), and displace water out of a gas jar.Will prove reactive properties after the very dilute soln has proved the Hydrogen.

Will test a bit with 0.1M and see.

[Krysia Lee]

Hi Everyone

I was just asked for calcium metal, we don't have any. It is to do the same prac as has been talked about above. I'm just wondering does everyone have calcium in there in chem stores and if you do how do you store it. Any info will be greatly appreciated.
Cheers
Krysia

[Rita]

We don't have Calcium. We use Sodium instead (been there for at least 8 years). Only ever used as Sodium in water demonstration.

[Labbie]

The CSIS tells us on page 67.
I Quota

" Calcium Metal or Granules 7-12 4.3 class dg pg 11 un or cas No 1401 7440-70-2
Toxic if ingested or by skin contact.
Evolves flammable hydrogen gas on contact with water, Hydrogen and air will explode if ignited: surface layer of calcium hydroxide is corrosive to skin & eyes.
Use in a fume cupboard if practicable, otherwise use small quantities in a well-ventilated area. Use eye & skin protection when splashes are possible.
The metal is much harder to cut than sodium. Do not mix calcium with sulphur or phosphorus, since the reaction is dangerously exothermic. Provide each student only a few grains of calcium. Purchase in small quantities and store in a tightly sealed container to exclude moisture & air.
Used to compare the reactivities of metals, with water, air, diluite acids. Readily oxidised in container.
end of quota"

4.3 is Dangerous when wet I think, so store with the other class 4 chemicals you may have.

[mtg]

It's in the Yr 8 book, "another way to make hydrogen", after the HCl and Mg pop test. With the Ca we just use water tho". Rate of reaction is diff strengths of HCl and Mg I think.

[lada]

We have calcium granules and I keep them under paraffin. I feel safer doing it.
Krysia, I can give you some, but I am in Collaroy.
Lada