1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
IrinaVladis [17]
3 years ago
15

Please answer each question! Due today! Will mark brainliest!

Chemistry
1 answer:
sasho [114]3 years ago
4 0

Answer:

1.They generate power only from the kinetic energy of moving water (current).

2.relating to the motions of fluids or the forces which produce or affect such motions — compare hydrostatic.

3. It uses water motion to generate a high-pressure liquid rather than electricity.

4. tidal currents, ocean currents or river currents into electrical power.

5.When flowing water is captured and turned into electricity, it is called hydroelectric power or hydropower. There are several types of hydroelectric facilities; they are all powered by the kinetic energy of flowing water as it moves downstream.

Explanation:

You might be interested in
A 20.0 mL 0.100 M solution of lactic acid is titrated with 0.100 M NaOH.
yan [13]

Answer:

(a) See explanation below

(b) 0.002 mol

(c) (i) pH = 2.4

(ii) pH = 3.4

(iii) pH = 3.9

(iv) pH = 8.3

(v) pH = 12.0

Explanation:

(a) A buffer solution exits after addition of 5 mL of NaOH  since after reaction we will have  both the conjugate base lactate anion and unreacted weak  lactic acid present in solution.

Lets call lactic acid HA, and A⁻ the lactate conjugate base. The reaction is:

HA + NaOH ⇒ A⁻ + H₂O

Some unreacted HA will remain in solution, and since HA is a weak acid , we will have the followin equilibrium:

HA  + H₂O ⇆ H₃O⁺ + A⁻

Since we are going to have unreacted acid, and some conjugate base, the buffer has the capacity of maintaining the pH in a narrow range if we add acid or base within certain limits.

An added acid will be consumed by the conjugate base A⁻ , thus keeping the pH more or less equal:

A⁻ + H⁺ ⇄ HA

On the contrary, if we add extra base it will be consumed by the unreacted lactic acid, again maintaining the pH more or less constant.

H₃O⁺ + B ⇆ BH⁺

b) Again letting HA stand for lactic acid:

mol HA =  (20.0 mL x  1 L/1000 mL) x 0.100 mol/L = 0.002 mol

c)

i) After 0.00 mL of NaOH have been added

In this case we just have to determine the pH of a weak acid, and we know for a monopric acid:

pH = - log [H₃O⁺] where  [H₃O⁺] = √( Ka [HA])

Ka for lactic acid = 1.4 x 10⁻⁴  ( from reference tables)

[H₃O⁺] = √( Ka [HA]) = √(1.4 x 10⁻⁴ x 0.100) = 3.7 x 10⁻³

pH = - log(3.7 x 10⁻³) = 2.4

ii) After 5.00 mL of NaOH have been added ( 5x 10⁻³ L x 0.1 = 0.005 mol NaOH)

Now we have a buffer solution and must use the Henderson-Hasselbach equation.

                            HA          +         NaOH          ⇒   A⁻ + H₂O

before rxn         0.002                  0.0005                0

after rxn    0.002-0.0005                  0                  0.0005

                        0.0015

Using Henderson-Hasselbach equation :

pH = pKa + log [A⁻]/[HA]

pKa HA = -log (1.4 x 10⁻⁴) = 3.85

pH = 3.85 + log(0.0005/0.0015)

pH = 3.4

iii) After 10.0 mL of NaOH have been ( 0.010 L x 0.1 mol/L = 0.001 mol)

                             HA          +         NaOH          ⇒   A⁻ + H₂O

before rxn         0.002                  0.001               0

after rxn        0.002-0.001                  0                  0.001

                        0.001

pH = 3.85 + log(0.001/0.001)  = 3.85

iv) After 20.0 mL of NaOH have been added ( 0.002 mol )

                            HA          +         NaOH          ⇒   A⁻ + H₂O

before rxn         0.002                  0.002                 0

after rxn                 0                         0                   0.002

We are at the neutralization point and  we do not have a buffer anymore, instead we just have  a weak base A⁻ to which we can determine its pOH as follows:

pOH = √Kb x [A⁻]

We need to determine the concentration of the weak base which is the mol per volume in liters.

At this stage of the titration we added 20 mL of lactic acid and 20 mL of NaOH, hence the volume of solution is 40 mL (0.04 L).

The molarity of A⁻ is then

[A⁻] = 0.002 mol / 0.04 L = 0.05 M

Kb is equal to

Ka x Kb = Kw ⇒ Kb = 10⁻¹⁴/ 1.4 x 10⁻⁴ = 7.1 x 10⁻¹¹

pOH is then:

[OH⁻] = √Kb x [A⁻]  = √( 7.1 x 10⁻¹¹ x 0.05) = 1.88 x 10⁻⁶

pOH = - log (  1.88 x 10⁻⁶ ) = 5.7

pH = 14 - pOH = 14 - 5.7 = 8.3

v) After 25.0 mL of NaOH have been added (

                            HA          +         NaOH          ⇒   A⁻ + H₂O

before rxn           0.002                  0.0025              0

after rxn                0                         0.0005              0.0005

Now here what we have is  the strong base sodium hydroxide and A⁻ but the strong base NaOH will predominate and drive the pH over the weak base A⁻.

So we treat this part as the determination of the pH of a strong base.

V= (20 mL + 25 mL) x 1 L /1000 mL = 0.045 L

[OH⁻] = 0.0005 mol / 0.045 L = 0.011 M

pOH = - log (0.011) = 2

pH = 14 - 1.95 = 12

7 0
3 years ago
PLEASE HURRY AND TELL ME THE ANWERS
lesantik [10]

Answer:

Explanation:

3 0
2 years ago
PLEASE FILL IN THE BLANKS IM DYING OMGGGGG
Sidana [21]
Neutrons: +1
that's all

5 0
3 years ago
How many protons electrons and neutrons does the isotope nitrogen 15 have
Ivenika [448]
Answer:

The atomic number of<span>N<span>157</span></span> 
The number of protons is 7
The number of electrons is 7
The number of neutrons is 8

Explanation:

The atomic number of Nitrogen is 7 because Nitrogen has 7 protons. 
The seven protons attract 7 electrons in the ground state.

If the atom had fewer or more than 7 protons the atom would not be Nitrogen.

The mass of the atom is the sum of protons and neutron. so

p + n = mass ( protons (p) and neutrons(n) both have an atomic mass of one

7 + n = 15 subtract 7 from both sides

<span>7−7+n=15−7</span>

n = 8

4 0
3 years ago
The combustion of 1 mole of CO according to the reaction CO(g) + ½O2(g) → CO2(g) + 67.6 kcal gives off how much heat?
Tomtit [17]
When the enthalpy value is given, we can calculate how much heat is use or produces in a given equation. 

67.6 kCal ---> 67.6 kCal= 1 mol of reaction
1 mol of reaction=  1 mol of CO (based on the coefficient)

so 1 mole of CO gives us 67.6 kCal of heat.

calculation:

1 mol CO\frac{67.5 kcal}{1 mol CO} = 67.5 kcal




5 0
3 years ago
Other questions:
  • Ultraviolet rays are absorbed by water in the atmosphere not absorbed by water in the atmosphere slowed down by water in the atm
    13·1 answer
  • For the second-order reaction below, the initial concentration of reactant A is 0.24 M. If the rate constant for the reaction is
    14·1 answer
  • What is the Hsol for KBr k+ + br- ? The lattice energy is –679 kJ, the enthalpy of hydration for is –336 kJ/mol, and the enthalp
    5·1 answer
  • Look this is a weird question to ask but am asking it anyways
    11·2 answers
  • What is the best way to determine if an aqueous solution of sodium nitrate is unsaturated
    6·1 answer
  • Which sample is a pure substance?
    15·2 answers
  • What is the density of a substance with a mass of 15.0 g and a volume of 5.0 mL?
    14·1 answer
  • How much force is needed to accelerate a 66 kg skier at 2 m/sec2
    7·1 answer
  • Is this a scientific model? Use complete sentences to explain why or why not
    8·1 answer
  • When a stone is dipped in a glass containing some water, the level of water rises but when a
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!