Identify each substance whether it is a pure substance or a mixture. If it is a pure substance, specify if it is a compound or an element, and if it is a mixture, specify if it is a heterogeneous or a homogeneoug mixture.
table salt, magnesium ribbon, burned magnesium riboon, iodine, starch, iodine crystals, sulfur in H2O, H2O added into a burned magnesium ribbon, magnesium ribbon plus H2O, mercury, carbon disulfide, salt dissolved in water, sulfur in carbon disulfide (did it dissolve?), salt in carbon disulfide (did it dissolve?), heated lead(II) nitrate, lead nitrate, groun sulfur and table salt, ground mercury with sulfur.
Please I need your help.
If you have resources, please share it with me. Thank you very much.
2006-12-27 14:08:25 · 2 answers · asked by jann kyle_upvcc 1 in Science & Mathematics ➔ Chemistry
To classify substances use the following question key:
1. How many different substances do you see?
(if more than one it is a heterogeneous mixture)
2. If you see only one, then ask: Is it made of only one kind of atom?
(if yes, it is a pure substance - element)
3. If it is made of more than one kind of atom then ask: are the components chemically combined with a definite composition?
(if yes, then it is a pure substance - compound)
4. If it is physically combined with a variable composition it is a homogeneous mixture.
In some of your examples you need to know what happened when you mixed things: if there was a new substance formed you've got a chemical reaction. If not, you have a physical change and the result is just a mixture.
Heterogeneous: sufur in water; magnesium ribbon plus water, sulfur in carbon disulfide; salt in carbon disulfide; ground sulfur with ground salt; mercury with ground sulfur [you can't grind the mercury, its a liquid].
elements: magnesium ribbon, iodine, iodine crystals, mercury
compounds: table salt, burned magnesium ribbon (produces new compounds), starch, carbon disulfide, lead nitrate, heated lead nitrate (produces new compounds)
Homogeneous mixtures: salt dissolved in water
The water added to the burned magnesium can be tricky. The product (magnesium oxide) when added to water will produce a new compound (magnesium hydroxide) but if you have lots of water the result will be a heterogeneous mixture since the new magnesium hydroxide is not soluble in the remaining water.
2006-12-28 01:02:51 · answer #1 · answered by The Old Professor 5 · 0⤊ 0⤋
it is a potasuim iodide with mercury under variable heating conditions
2013-11-02 15:07:42 · answer #2 · answered by shereef 1 · 0⤊ 0⤋