Solution A has a pH of 4.

How do human obtain the nitrogen they use in their bodies

Komok [63]

Humans get the nitrogen they need by eating vegetebles or other meat that contain nitrogen. hope it helps :)

8 0

3 years ago

The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolvin

nadya68 [22]

Answer:

(a) 0.039

(b) 0.384 M

(c) 0.373 M

Explanation:

We have the following data:

d(C₇H₈) = 0.867 g/mL

d(C₄H₄S) = 1.065 g/mL

V(C₇H₈) = 250.0 mL

mass(C₄H₄S) = 8.10 g

(a) The mole fraction of C₄H₄S in the solution is the number of moles of C₄H₄S divided into the total moles of the solution:

X(C₄H₄S) = moles C₄H₄S/ total moles

To calculate the moles, we need the molecular weight (MW) of each compound:

MW(C₄H₄S) = (4 x 12 g/mol) + (4 x 1 g/mol) + 32 g/mol = 84 g/mol

MW(C₇H₈) = (7 x 12 g/mol) + (8 x 1 g/mol) = 92 g/mol

Thus, we calculate the moles of C₄H₄S by dividing the mass into the MW(C₄H₄S):

moles C₄H₄S = mass(C₄H₄S)/MW(C₄H₄S)= 8.10 g/(84 g/mol) = 0.096 moles

Then, we have to calculate the moles of C₇H₈. First, we need the mass, obtained from the product of the density by the volume:

mass(C₇H₈)= d(C₇H₈) x V(C₇H₈) = 0.867 g/mL x 250.0 mL = 216.75 g

Thus, we divide the mass of C₇H₈ into the MW to calculate the moles of C₇H₈:

moles C₇H₈ = mass(C₇H₈)/MW(C₇H₈) = 216.75 g/(92 g/mol) = 2.35 moles

The total moles is obtained from the addition of the moles of the solute (C₄H₄S) and the solvent (C₇H₈):

total moles = moles C₄H₄S + moles C₇H₈ = 0.096 moles + 2.35 moles = 2.45 moles

Finally, we calculate the mole fraction of C₄H₄S:

X(C₄H₄S) = moles C₄H₄S/ total moles = 0.096 moles/2.45 moles = 0.039

(b) The molarity of C₄H₄S is calculated as follows:

M(C₄H₄S) = moles C₄H₄S/1 liter solution

Assuming that the total volume of the solution is the volume of solvent (C₇H₈), we calculate the molarity of C₄H₄S by dividing the moles into the volume of solvent in liters:

V(C₇H₈) = 250.0 mL = 0.250 L

M(C₄H₄S) = 0.096 moles/(0.250 L) = 0.384 mol/M = 0.384 M

(c) Assuming that the volumes of solute and solvent are additive, we can add the volumes of C₄H₄S and C₇H₈. First, we need the volume of C₄H₄S, which can be calculated from the mass and density:

V(C₄H₄S) = mass(C₄H₄S)/ d(C₄H₄S) = 8.10 g/(1.065 g/mL) = 7.606 mL = 0.0076 L

Now, we add the volumes:

total volume = V(C₇H₈) + V(C₄H₄S) = 0.250 L + 0.0076 L = 0.2576 L

Finally, we recalculate the molarity of C₄H₄S:

M(C₄H₄S)= moles C₄H₄S/ total volume = 0.096 moles/0.2576 L = 0.373 M

7 0

3 years ago

NEED HELP with 7. 8. 9. 10. 11. 12. And 14 !!

aleksley [76]

Answer:

1. 0.00040 calories

2. 8.57 calories

3. 0.196 calories

4. 68 calories

5. 243 calories

6. 83680 joules

7. 1,054,368 joules

8. 2.45 calories

9. 556 (it says calories to calories so it wouldn't change)

10. 28367.52 joules

11. 59.6 calories

12. 449.6 joules

13. 0.00234 calories

14. 23292.328 joules

15. 22877693.6 joules

Hope this helps!

Explanation:

6 0

3 years ago

In a nuclear reaction, which quantity is the same before and after the change?(1 point)

swat32

Answer:

in alpha decay, shown in Fig. 3-3, the nucleus emits a 4He nucleus, an alpha particle. Alpha decay occurs most often in massive nuclei that have too large a proton to neutron ratio. An alpha particle, with its two protons and two neutrons, is a very stable configuration of particles. Alpha radiation reduces the ratio of protons to neutrons in the parent nucleus, bringing it to a more stable configuration. Many nuclei more massive than lead decay by this method.

Explanation:

6 0

3 years ago

Explain in writing how ionic bonds work using Sodium Chloride as an example.

Alisiya [41]

The goal of an element is to obtain a noble gas configuration (obtaining a full valence shell). Therefore, certain elements will either gain or lose electrons in order to obtain this full valence shell. In the case of sodium chloride, it is easy for sodium (having one valence electron) to give up its one electron. Chlorine (having seven valence electrons) wants sodium’s electron because it completes its outer shell and chlorine obtains this noble gas configuration. Ionic bonds always involve a transfer of electrons.

8 0

3 years ago