Answer:
The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
Explanation:
Where:
Q = heat absorbed or heat lost
c = specific heat of substance
m = Mass of the substance
ΔT = change in temperature of the substance
We have mass of copper = m = 25.3 g
Specific heat of copper = c = 0.385 J/g°C
ΔT = 39°C - 22°C = 17°C
Heat absorbed by the copper :
The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
As per the given chemical formula- Na2CO3.10H2O, one mole of the chemical compound contains 13 moles of oxygen atoms. Hence
Number of moles of oxygen atoms in one mole of Na2CO3.10H2O = 13
number of moles of oxygen atoms in 0.2 moles of Na2CO3.10H2O = 13 X 0.2 = 2.6
Now, one mole of a substance contains 6.022 X 10^23 particles of the substance. Thus
number of atoms of oxygen in one mole of oxygen atom = 6.022 X 10^23
number of moles of oxygen atoms in 2.6 moles of oxygen atoms = 2.6 X 6.022 X 10^23 = 15.657 X 10^23
= 1.566 X 10^24
Thus, there are 1.566 X 10^24 atoms of oxygen in 0.2 moles of Na2CO3.10H2O.
4.7
Answer:
1. 4-ethyl-1-heptene
2. 6-ethyl-2-octene
3. 1-butyne
Explanation:
The compounds are named according to IUPAC rules.
Compound 1:
- Identify the longest carbon chain. This chain is called the parent chain.
- Identify all of the substituents (groups appending from the parent chain).
- The parent chain is numbered so that the multiple bonds have the lowest numbers (double has the priority over alkyl substituents).
- The longest chain contains 7 carbon atoms, so taken the name hept.
- The double bond between C1 and C2, so take no. 1 and add the suffix ene to hept "1-heptene".
- The ethyl group is the alkyl substituent on position 4.
- So the name is 4-ethyl-1-heptene.
Compound 2:
- Identify the longest carbon chain. This chain is called the parent chain.
- Identify all of the substituents (groups appending from the parent chain).
- The parent chain is numbered so that the multiple bonds have the lowest numbers (double has the priority over alkyl substituents).
- The longest chain contains 8 carbon atoms, so taken the name oct.
- The double bond between C2 and C3, so take no. 2 and add the suffix ene to oct "2-octene".
- The ethyl group is the alkyl substituent on position 6.
- So the name is 6-ethyl-2-octene.
Compound 3:
- Identify the longest carbon chain. This chain is called the parent chain.
- Identify all of the substituents (groups appending from the parent chain), there is no substituents.
- The parent chain is numbered so that the multiple bonds have the lowest numbers (Triple bond here take the lowest number).
- The longest chain contains 4 carbon atoms, so taken the name but.
- The triple bond between C1 and C2, so take no. 1 and add the suffix yne to but "1-butyne".
I cant help unless there is an article..
Answer:
A. Water
Explanation:
H2O means that there are two hydrogen and one oxygen in every water molecule.
