All categories

2 years ago

1. Calculate how many moles of glycine are in a 130.0-g sample of glycine.2. Calculate the percent nitrogen by mass in glycine.

Chemistry

1 answer:

Alexxx [7]2 years ago

4 0

Answer:

$n=1.732mol$

$\% N=18.7\%$

Explanation:

Hello!

In this case, since the molecular formula of glycine is C₂H₅NO₂, we realize that the molar mass is 75.07 g/mol; thus, the moles in 130.0 g of glycine are:

$n=130.0g*\frac{1mol}{75.07 g}\\\\ n=1.732mol$

Furthermore, we can notice 75.07 grams of glycine contains 14.01 grams of nitrogen; thus, the percent nitrogen turns out:

$\% N=\frac{14.01}{75.07}*100\% \\\\\% N=18.7\%$

Best regards!

You might be interested in

When heated, calcium hydroxide and ammonium chloride react to produce ammonia gas, water vapor, and solid calcium chloride.

NNADVOKAT [17]

Answer:

13.73g

Explanation:

mass of reactants = mass of products.

Mass reactants = 5.00 g + 10.00 g = 15.00 g

Mass products = 1.27g + mass of ammonia and water vapor

Mass of ammonia and water vapor

15.00g – 1.27 g = 13.73 g

3 0

2 years ago

A gas mixture with 4 mol of Ar, x moles of Ne, and y moles

maks197457 [2]

Answer:

a) $\Delta G_{mixing}=\frac{R*T}{12}*[4*ln (1/3) +x*ln (x/12) +(8-x)*ln ((8-x)/12)]$

b) $x=4$

c) $\Delta G_{max}=-2721.9 J/mol$

Explanation:

Gas mixture:

$n_{Ar}= 4 mol$

$n_{Ne}= x mol$

$n_{Xe}= y mol$

$n_{tot}= n_{Ar} + n_{Ne} + n_{Xe}=3*n_{Ar}$

$n_{Ne} + n_{Xe}=2*n_{Ar}$

$x + y=8 mol$

$y=8 mol- x$

Mol fractions:

$x_{Ar}=\frac{4 mol}{12 mol}=1/3$

$x_{Ne}=\frac{x mol}{12 mol}=x/12$

$x_{Xe}=\frac{8 - x mol}{12 mol}=(8-x)/12$

Expression of $\Delta G_{mixing}$

$\Delta G_{mixing}=R*T*\sum_{i]*x_i*ln (x_i)$

$\Delta G_{mixing}=R*T*[1/3*ln (1/3) +x/12*ln (x/12) +(8-x)/12*ln ((8-x)/12)]$

$\Delta G_{mixing}=\frac{R*T}{12}*[4*ln (1/3) +x*ln (x/12) +(8-x)*ln ((8-x)/12)]$

Expression of $\Delta G_{max}$

$\frac{d \Delta G_{mixing}}{dx}=0$

$\frac{d \Delta G_{mixing}}{dx}=\frac{R*T}{12}*[ln (x/12)+12-ln ((8-x)/12)-12]$

$0=\frac{R*T}{12}*[ln (x/12)-ln ((8-x)/12)$

$0=[ln (x/12)-ln ((8-x)/12)$

$ln (x/12)=ln ((8-x)/12)$

$x=(8-x)$

$x=4$

$\Delta G_{max}=\frac{8.314*298}{12}*[4*ln (1/3) +4*ln (4/12) +(8-4)*ln ((8-4)/12)]$

$\Delta G_{max}=\frac{8.314*298}{12}*[4*ln (1/3) +4*ln (1/3) +(4)*ln (1/3)]$

$\Delta G_{max}=\frac{8.314*298}{12}*[12*ln (1/3)]$

$\Delta G_{max}=-2721.9 J/mol$

4 0

2 years ago

A sample of helium gas in a balloon is compressed from 4.0 L to 3.2 L at a constant temperature. If the pressure of the gas in t

vampirchik [111]

Answer:

286 kPa

Explanation:

Boyles law states that volume of gas is inversely proportional to pressure o gas for a fixed amount of gas at constant temperature

P1V1 = P2V2

where P1 is pressure and V1 is volume at first instance

P2 is pressure and V2 is volume at the second instance

substituting the values in the equation

229 kPa x 4.0 L = P2 x 3.2 L

P2 = 286.25 kPa

the new pressure is 286 kPa

4 0

2 years ago

Electrons are capable of emmiting engery in the form of light at very narrow ranges of wavelengths. these wavelengths can be mea

sukhopar [10]

C) energy level

Looking at quantum mechanics, we see that electrons exist at certain energy levels. When they get excited, they’ll jump from one energy state to a higher energy state and down. We can the. Look at the color it admits and determine what the energy level is.

5 0

2 years ago

What is the total number of electron pairs shared between the two atoms in an O2 molecule?

vodka [1.7K]

The answer is (2) 2 pairs. The oxygen atoms combine to get stable structure. So after the combination, each atom needs to have 8 electrons. So when they share 4 electrons can satisfy this requirement. Then there are 2 pairs shared.

8 0

2 years ago