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4 years ago

What is the value of n in CH3(CH2)nCH3 if the name of the hydrocarbon is heptane

Chemistry

2 answers:

Ksenya-84 [330]4 years ago

5 0

Answer:

n+5 so the correct answer is b) 5

Explanation:

just did review on edge

LekaFEV [45]4 years ago

4 0

Answer:

n = 5.

Explanation:

How many carbon atoms in total in this straight-chain hydrocarbon?

The prefix of the IUPAC name of a hydrocarbon (the part before -ane) shows the number of carbon atoms on the longest carbon chain.

$\begin{array}{c|c}\text{Number of Carbon}\\ \text{atoms in backbone} & \text{Prefix}\\[-0.5em]\multicolumn{2}{c}{\rule{5cm}{0.5pt}}\\1& \text{meth-} \\ 2&\text{eth-} \\ 3&\text{prop-}\\4 & \text{but-}\\5 & \text{pent-} \\ 6 & \text{hex-} \\ 7 & \text{hept-} \\8 & \text{oct-}\\ \dots & \dots\end{array}$ .

Name of this hydrocarbon: heptane;
Prefix: hept-;
Number of carbon atoms in the longest chain: 7.

Hence the structure:

$\text{CH}_3\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_3$ .

All the $\text{-CH}_2\text{-}$ in the formula might look redundant. " $\text{CH}_2$ " appears five times in a row and may be condensed into $(\text{CH}_2)_5$ . Hence the condensed formula:

$\text{CH}_3\text{-}{(\text{CH}_2)_{\bf5}\text{-CH}_3$ .

Therefore $n = 5$ .

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3 years ago

PLEASE HELP! 25 POINTS!!!! I got the #1, just not #2 and #3. An industrial chemical company has opened a new plant that will pro

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Answer :

Part 1 : Balanced reaction, $3H_2(g)+N_2(g)\rightarrow 2NH_3(g)$

Part 2 : The theoretical yield of $NH_3$ gas = 440.96 g

Part 3 : The % yield of ammonia is 90.03 %

Solution : Given,

Mass of $N_2$ = 475 g

Molar mass of $N_2$ = 28 g/mole

Molar mass of $NH_3$ = 17 g/mole

Experimental yield of $NH_3$ = 397 g

Answer for Part (1) :

The balanced chemical reaction is,

$3H_2(g)+N_2(g)\rightarrow 2NH_3(g)$

Answer for Part (2) :

First we have to calculate the moles of $N_2$ .

$\text{Moles of }N_2=\frac{\text{ Mass of }N_2}{\text{ Molecular mass of }N_2}=\frac{475g}{28g/mole}=16.96moles$

From the given reaction, we conclude that

1 moles of $N_2$ gas react to give 2 moles of $NH_3$ gas

16.96 moles of $N_2$ gas react to give $\frac{2}{1}\times 16.96=33.92$ moles of $NH_3$ gas

Now we have to calculate the mass of $NH_3$ gas.

$\text{ Mass of }NH_3=\text{ Moles of }NH_3\times \text{ Molar mass of }NH_3$

$\text{ Mass of }NH_3=(33.92moles)\times (17g/mole)=440.96g$

Therefore, the theoretical yield of $NH_3$ gas = 440.96 g

Answer for Part (3) :

Formula used for percent yield :

$\% \text{ yield of }NH_3=\frac{\text{ Experimental yield of }NH_3}{\text{ Theoretical yield of }NH_3}\times 100$

$\% \text{ yield of }NH_3=\frac{397g}{440.96g}\times 100=90.03\%$

Therefore, the % yield of ammonia is 90.03 %

3 0

3 years ago

Matter that has a uniform and defined composition is called a

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Answer - A substance is matter that has a uniform and definite composition. All samples of substances, sometimes called pure substances, have identical properties.

6 0

3 years ago

Consider a transition of the electron in the hydrogen atom from n=3 to n=7.

kow [346]

Answer:

For a: The wavelength of light is $1.005\times 10^{-6}m$

For b: The light is getting absorbed

Explanation:

For a:

To calculate the wavelength of light, we use Rydberg's Equation:

$\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )$

Where,

$\lambda$ = Wavelength of radiation

$R_H$ = Rydberg's Constant = $1.097\times 10^7m^{-1}$

$n_f$ = Higher energy level = 7

$n_i$ = Lower energy level = 3

Putting the values in above equation, we get:

$\frac{1}{\lambda }=1.097\times 10^7m^{-1}\left(\frac{1}{3^2}-\frac{1}{7^2} \right )\\\\\lambda =1.005\times 10^{-6}m$

Hence, the wavelength of light is $1.005\times 10^{-6}m$

For b:

There are two ways in which electrons can transition between energy levels:

Absorption spectra: This type of spectra is seen when an electron jumps from lower energy level to higher energy level. In this process, energy is absorbed.
Emission spectra: This type of spectra is seen when an electron jumps from higher energy level to lower energy level. In this process, energy is released in the form of photons.

As, the electron jumps from lower energy level to higher energy level. The wavelength is getting absorbed.

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Explanation :

Formula used :

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