All categories

1 year ago

Hi can someone hellp this is grade 7

Chemistry

2 answers:

bearhunter [10]1 year ago

5 0

Answer:

Kinetic energy

Explanation:

E.g. water moving in dams are used to produce electricity

I am also in Grade 7 Lol

saw5 [17]1 year ago

3 0

Explanation:

option B kinetic energy

hope this helps you!

You might be interested in

Which of the following is most likely to cause the particles in a chemical change to slow down

Nady [450]

C. Lowering the temperature

At the lower temperature, particles have less kinetic energy, so they move slower.

7 0

2 years ago

Why can scientists ignore the forces of attraction between particles in a gas under ordinary conditions

Alika [10]

Scientists ignore the forces of attraction between particles in a gas under ordinary conditions because the particles in a gas are apart and moving fast, rather than clustered and moving slow, therefore the forces of attraction are too weak to have a visible effect.

3 0

2 years ago

Iron is extracted from iron oxide in the Blast Furnace: Fe 2 O 3 + 3 CO → 2 Fe + 3 CO 2

arsen [322]

a. mass of iron = 69.92 g

b. percent yield = 93%

<h3>Further eplanation </h3>

Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated

General formula:

Percent yield = (Actual yield / theoretical yield )x 100%

An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients

Reaction

Fe₂O₃+3CO⇒2Fe+3CO₂

MW Fe₂O₃ : 159.69 g/mol

mol Fe₂O₃

$\tt \dfrac{100}{159,69}=0.626$

mol Fe₂O₃ : mol Fe = 1 : 2

mol Fe :

$\tt \dfrac{2}{1}\times 0.626=1.252$

mass of Fe(Ar=55.845 g/mol) :

$\tt 1.252\times 55.845=69.92~g$

actual yield = 65 g

theoretical yield = 69.92 g

percent yield :

$\tt =\dfrac{65}{69.92}=0.93=93\%$

8 0

2 years ago

Convert this temperature from F to C 26.6°c 93.600 62.2°C 5.7°C

eduard

The answer for this is 26.6°c

3 0

2 years ago

The activation energy for proline isomerization of a peptide depends on the identity of the preceding residue and obeys Arrheniu

MAVERICK [17]

Answer:

Activation energy of phenylalanine-proline peptide is 66 kJ/mol.

Explanation:

According to Arrhenius equation- $k=Ae^{\frac{-E_{a}}{RT}}$ , where k is rate constant, A is pre-exponential factor, $E_{a}$ is activation energy, R is gas constant and T is temperature in kelvin scale.

As A is identical for both peptide therefore-

$\frac{k_{ala-pro}}{k_{phe-pro}}=e^\frac{[E_{a}^{phe-pro}-E_{a}^{ala-pro}]}{RT}$

Here $\frac{k_{ala-pro}}{k_{phe-pro}}=\frac{0.05}{0.005}$ , T = 298 K , R = 8.314 J/(mol.K) and $E_{a}^{ala-pro}=60kJ/mol$

So, $\frac{0.05}{0.005}=e^{\frac{[E_{a}^{phe-pro}-(60000J/mol)]}{8.314J.mol^{-1}.K^{-1}\times 298K}}$

$\Rightarrow$ $E_{a}^{phe-pro}=65705J/mol=66kJ/mol$ (rounded off to two significant digit)

So, activation energy of phenylalanine-proline peptide is 66 kJ/mol

7 0

2 years ago