We are given that the balanced chemical reaction is:
cacl2⋅2h2o(aq) +
k2c2o4⋅h2o(aq) --->
cac2o4⋅h2o(s) +
2kcl(aq) + 2h2o(l)
We known that
the product was oven dried, therefore the mass of 0.333 g pertains only to that
of the substance cac2o4⋅h2o(s). So what we will do first is to convert this
into moles by dividing the mass with the molar mass. The molar mass of cac2o4⋅h2o(s) is
molar mass of cac2o4 plus the
molar mass of h2o.
molar mass cac2o4⋅h2o(s) = 128.10
+ 18 = 146.10 g /mole
moles cac2o4⋅h2o(s) =
0.333 / 146.10 = 2.28 x 10^-3 moles
Looking at
the balanced chemical reaction, the ratio of cac2o4⋅h2o(s) and k2c2o4⋅h2o(aq) is
1:1, therefore:
moles k2c2o4⋅h2o(aq) = 2.28
x 10^-3 moles
Converting
this to mass:
mass k2c2o4⋅h2o(aq) = 2.28
x 10^-3 moles (184.24 g /mol) = 0.419931006 g
Therefore:
The mass of k2c2o4⋅<span>h2o(aq) in
the salt mixture is about 0.420 g</span>
Shred red cabbage ~ (3/4 of a very small head)
Put the cabbage pieces in a small container ~ ( you can use a Pyrex-4-cup measure, a bowl or even a plastic zipper bag)
Cover the cabbage with very hot water. Let it sleep until the water has cooled. (somewhere between lukewarm and room-temperature)
The purple liquid you've made is your indicator.
Pour it into a container and compost the cabbage.
Now look for substances that may be acids or bases.
Liquids are good, like fruits.
You can also use solids around for baking are good too. (such as baking soda, salt, sugar, cream of tartar...)
Get containers for mixing (such as tea cups, because they are small, shallow and white inside)
Pour the indicator into the tea cups and add an acid or base.
Lemon juice, rice wine vinegar, and apple cider vinegar, turn the cabbage-water indicator into a pink.
Orange juice or fresh oranges (same thing) turn the cabbage-water indicator into an orangish-pinkish color.
Baking soda turns the cabbage-water indicator blue.
Milk (non-fat) turns the cabbage-water indicator turn opaque and milky, yet purple.
An egg white (which won't get into the solution immediately until after a lot of stirring) turns the cabbage-water indicator blue.
Hint:
Bases mostly turn the indicator towards blue-ish colors such as purple, light blue, dark blue, opaque blue...
Acids mostly turn the indicator towards pink-ish colours such as orange-ish pink, floral pink...
(You'll have to keep on testing the cabbage-water indicator in after a day or two to see if the indicator quality persists or degrades.
The answer is heat.
To use a glue gun, it has to use heat to heat up so that it can melt the glue.
To form a salt compound, the acid contribute a NON METAL ION and the base contributes a METAL ION.
In chemistry, acid and base react together to form salt and water only. For the salt formed, the positive metal ion comes from the base while the negative non metal ion comes from the acid.
