Help with this question!!!

Daniel has a sample of pure copper. Its mass is 89.6 grams (g), and its volume is 10 cubic centimeters (cm3). What’s the density

vlada-n [284]

Density = mass /volume = 89.6/10 = 8.96gm/cm^3.

8 0

3 years ago

A concentration cell is built based on the following half reactions by using two pieces of zinc as electrodes, two Zn2+ solution

Lana71 [14]

Explanation:

The given reaction at cathode will be as follows.

At cathode: $Zn^{2+} + 2e^{-} \rightarrow Zn$ , $E_{o}$ = -0.761 V

At anode: $Zn \rightarrow Zn^{2+} + 2e^{-}$ , $E_{o}$ = 0.761

Therefore, net reaction equation will be as follows.

$Zn^{2+} + Zn \rightarrow Zn + Zn^{2+}$

Initial: 0.129 - - 0.427

Change: -0.047 - - -0.047

Equilibrium: (0.129 - 0.047) (0.427 - 0.047)

= 0.082 = 0.38

As $E^{o}_{cell}$ for the given reaction is zero.

Hence, equation for calculating new cell potential will be as follows.

E_{cell} = $E^{o}_{cell} - \frac{RT}{nF} ln \frac{[Zn^{2+}]_{products}}{[Zn^{2+}]_{reactants}}$

= $0 - \frac{8.314 atm L/mol K \times 291 K}{2 \times 96500} ln \frac{0.38}{0.082}$

= 0.019

Thus, we can conclude that the cell potential of the given cell is 0.019.

3 0

4 years ago

Use the following table to answer the question. Strong acids Weak acids Weak bases Strong bases HBr CH3COOH NH3 NaOH HCl HF NH4O

Y_Kistochka [10]

Answer: The salt which has the highest pH is $CH_3COONa$

Explanation: Salts are formed by the reaction of acid and base. General equation for the generation of salt is given by:

$HX+BOH\rightarrow BX+H_2O$

The given salts are formed from the reaction of acids and bases.

1) $K_2SO_4$

This is a salt formed by the reaction of strong base (KOH) and strong acid $(H_2SO_4)$ . So, this salt is a neutral salt.

$H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O$

2) $CuSO_4$

This is a salt which is formed by the reaction of weak base $(Cu(OH)_2)$ and strong acid $(H_2SO_4)$ . So, this salt is an acidic salt.

$H_2SO_4+Cu(OH)_2\rightarrow CuSO_4+2H_2O$

3) $NH_4Cl$

This is a salt which is formed by the reaction of weak base $(NH_3)$ and strong acid (HCl). So, this salt is an acidic salt.

$HCl+NH_3\rightarrow NH_4Cl$

4) $CH_3COONa$

This is a salt which is formed by the reaction of strong base (NaOH) and weak acid $(CH_3COOH)$ . So, this salt is a basic salt.

$CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O$

Now, we have to find the salt which has the highest pH value.

Highest pH value means that the salt must be basic in nature and from the given salts, only $CH_3COONa$ is basic salt. Hence, this salt has the highest pH value.

6 0

3 years ago

Read 2 more answers

How many milliliters (mL) of 0.610 M NaOH solution are needed to neutralize 20 mL of a 0.245 M H2SO4 solution?

jenyasd209 [6]

There is to know the b

6 0

3 years ago

If I initially have 4.0 L of a gas at a pressure of 1.1 atm and a temperature of 298 K, what will the volume be if I increase th

DochEvi [55]

Answer:

1.34L

Explanation:

1 torr = 0.00132atm

P2= 2584torr = 3.41atm

T2= 37°C = 273+37 = 310K

Using combined gas law

P1V1/T1 = P2V2/T2

(1.1×4.0)/298 = (3.41 × V2)/310

V2= (1.1×4×310)/(298×3.41)

V2= 1.34L

4 0

3 years ago