Answer:
Paraffin oil is used for determination of boiling point and melting point for the following reasons: It has a very high boiling point and so it can be used to maintain high temperatures in the boiling and melting point apparatus without loss of the substance.
Answer:
Given the following list of densities, which materials would float in a molten vat of lead provided that they do not themselves melt?
Densities (g/mL): lead = 11.4, glass = 2.6, gold = 19.3, charcoal = 0.57, platinum = 21.4.
glass and charcoal
Explanation:
The density of molten lead is about 10.65Kg/m^3
By Archimedes principles, the buoyancy of an object in a fluid is proportional to the mass of fluid displaced
which in turn is proportional to the object's density
Generally an object well float when placed on a denser medium
glass =2.6, and charcoal =0.57 are both less dense so they will float on Lead
Answer:
- <u>C₂H₄</u> (option number 4)
Explanation:
A hydrocarbon with a <em>double bond</em> in its carbon skeleton is an alkene and has the general form:
-
.
This is, the number of hydrogen atoms is twice the number of carbon atoms.
On the other hand, alkanes have only single bonds, and the compounds with a triple bond in its carbon skeleton are alkynes.
Review each choice:
1) <u>C₃H₈:</u>
- In this case, the number of hydrogen atoms is 2×3 + 2 = 6 + 2 = 8, which is corresponds to an alkane, not an alkene.
2)<u> C₂H₆</u>
- For this, the number of hydrogen atoms is 2 × 2 + 2 = 4 + 2 = 6. Again an alkane, not alkene.
3) <u>CH₄</u>
- Hydrogen atoms: 1 × 2 + 2 = 4 ⇒ an alkane
4) <u>C₂H₄ </u>
- Hydrogen atoms: 2 × 2 = 4. This is precisely the relation for an alkene, so this is the hydrocarbon that has a double bond in its carbon skeleton.
- The chemical formula may be writen as CH₂ = CH₂, to show the double bond.
So, this is the correct answer.
5) <u>C₂H₂</u>
- Hydrogen atoms: 2 × 2 - 2 = 4 - 2 = 2. This relation of carbon and hydrogen atoms corresponds to a compound with triple bond, i.e an alkyne: CH≡CH.
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Answer:
2
Explanation:
The total number of atoms in silver sulfate Ag2SO4 is 2