When may a hypothesis be revised?

The movement of the earths plates is also called:

Ksenya-84 [330]

The movement of the Earth's plates is called Plate Tectonics. Hope this helps! :D

4 0

4 years ago

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Please help I’ll give brainliest

yuradex [85]

Halogens. Ex. fluorine can be the gas,bromine can be the liquid, and iodine could a solid all under room conditions.

4 0

4 years ago

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At − 12.0 ∘ C , a common temperature for household freezers, what is the maximum mass of sorbitol (C6H14O6) you can add to 2.00

allochka39001 [22]

Answer:

2,347.8 grams

Explanation:

The freezing point depression Kf of water = 1.86° C / molal.

To still freeze at -12° C, then the molality of the solution 12/ 1.86 = 6.45 moles

The molecular weight of sorbitol (C6H14O6)is:

6 C = 6 ×12 = 72

14 H = 14 × 1 = 14

6 O = 6 × 16 = 96

...giving a total of 182

So one mole of sorbitol has a mass of 182 grams.

Since there are 2 kg of water, 2 × 6.45 moles = 12.9 moles can be added to the water to get the 12° C freezing point depression.

Therefore

grams = moles × molar mass

12.9 moles × 182 grams / mole = 2,347.8 grams of sorbitol can be added and still freeze

7 0

3 years ago

The graph shows the amount of a gaseous product formed over time during two trials of a reaction. A different concentration of a

makkiz [27]

Trial 1 has a lower concentration of the reactant because the because the average rate of the reaction is lower.

<h3>What is a reaction?</h3>

The term reaction has to do with the combination of reactants in order to yield products. Now we know that the reaction profile is used to show the interaction that exists between the reactants and the products.

The y-axis of the graph is for the amount while the x axis of the graph is the reaction time. The rate of reaction is the time taken for a given amount of products to appear or for a given amount of reactants to disappear.

Thus, from the graph, we can see that trial 1 has a lower concentration of the reactant because the because the average rate of the reaction is lower.

Learn more about rate of reaction:brainly.com/question/24266729

#SPJ1

5 0

2 years ago

What is the final pH of a solution with an initial concentration of 2.5mM Ascorbic acid (H2C6H6O6) which has the following Kas:

riadik2000 [5.3K]

Answer:

pH = 3.39

Explanation:

The equilibrium in water of ascorbic acid (With its conjugate base) is:

H₂C₆H₆O₆(aq) + H₂O(l) ⇄ HC₆H₆O₆⁻(aq) + H₃O⁺(aq)

<em>Where the acidic dissociation constant is written as:</em>

Ka = 7.9x10⁻⁵ = [HC₆H₆O₆⁻] [H₃O⁺] / [H₂C₆H₆O₆]

H₂O is not taken in the Ka expression because is a pure liquid.

As initial concentration of H₂C₆H₆O₆ is 2.5x10⁻³M, the equilibrium concentration of each species in the equilibrium is:

[H₂C₆H₆O₆] = 2.5x10⁻³M - X

[HC₆H₆O₆⁻] = X

[H₃O⁺] = X

Replacing in the Ka expression:

7.9x10⁻⁵ = [X] [X] / [2.5x10⁻³M - X]

1.975x10⁻⁷ - 7.9x10⁻⁵X = X²

Solving for X:

X = -0.00048566→ False solution, there is no negative concentrations

X = 0.00040666 → Right solution

As [H₃O⁺] = X, [H₃O⁺] = 0.00040666

pH is defined as -log [H₃O⁺];

pH = -log 0.00040666,

5 0

3 years ago