The sum of the masses of the reactants must equal the sum of the masses of the products; as required by
the Principle of Conservation of Mass.
Answer:
1.75M
Explanation:
molarity = number of moles of solute/ number of L of solution =
=0.35 mol/0.2L = 1.75 mol/L = 1.75 M
Answers:
1. 3-ethyl-3-methylheptane; 2. 2,2,3,3-tetramethylpentane; 3. hexa-2,4-diene.
Explanation:
<em>Structure 1
</em>
- Identify and name the longest continuous chain of carbon atoms (the main chain has 7 C; ∴ base name = heptane).
- Identify and name all the substituents [a 1C substituent (methyl) and a 2C substituent (methyl).
- Number the main chain from the end closest to a substituent.
- Identify the substituents by the number of the C atom on the main chain. Use hyphens between letters and numbers (3-methyl, 3-ethyl).
- Put the names of the substituents in alphabetical order in front of the base name with no spaces (3-ethyl-3-methylheptane)
<em>Structure 2</em>
- 5C. Base name = pentane
- Four methyl groups.
- Number from the left-hand end.
- If there is more than one substituent of the same type, identify each substituent by its locating number and use a multiplying prefix to show the number of each substituent. Use commas between numbers (2,2,3,3-tetramethyl).
- The name is 2,2,3,3-tetramethylpentane.
<em>Structure 3
</em>
- Identify and name the longest continuous chain of carbon atoms that passes through as many double bonds as possible. Drop the <em>-ne</em> ending of the alkane to get the root name <em>hexa-</em>.
- (No substituents).
- Number the main chain from the end closest to a double bond.
- If there is more than one double bond use a multiplying prefix to indicate the number of double bonds (two double bonds = diene) and use the smaller of the two numbers of the C=C atoms as the double bond locators (2,4-diene)
- Put the functional group name at the end of the root name (hexa-2,4-diene).
<em>Note</em>: The name 2,4-hexadiene is <em>acceptable</em>, but the <em>Preferred IUPAC Name</em> puts the locating numbers as close as possible in front of the groups they locate.
molar mass of methane CH4
= C + 4 H
= 12.0 + 4 x 1.008
= 12.0 + 4.032
= 16.042g/mol
7.31 x 10^25 molecules x <u> 1 mole CH4 </u> = 121.43 moles
6.02 x 10^23 CH4 molecules
121.43 moles CH4 are present.