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3 years ago

Which statements describe a good hypothesis? Check all that apply.

Chemistry

2 answers:

Natalka [10]3 years ago

5 0

Answer:

- A good hypothesis can be tested.

- A good hypothesis provides a possible explanation to answer a scientific question.

- A good hypothesis does not always have to be based on prior knowledge or research.

Explanation:

The reason being because hypothesis are questions asked before the experiment. They usually involve the testable question and the experiment answers it, but not always. A good hypothesis doesn't need to have accurate results.

Oxana [17]3 years ago

5 0

Answer:B : A good hypothesis can be tested. C:A good hypothesis leads to a test with measurable results. E: A good hypothesis provides a possible explanation to an answer a scientific question ( B, C, E)

Explanation:Just took the (Assignment) quiz

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HELP DUE MONDAY!!<br> Don’t understand

Katyanochek1 [597]

Answer:

Concept: Chemical Analysis

You need to start by graphing the data and then analyzing it.
We can see that the horse has a distance in meters of 980 at the end of the 10 seconds hence it is the fastest.
The horse line has a linearly representation, while the alternate line has parabolic tendencies towards the end. The steeper line indicates a faster change in time or velocity which results in a greater distance traveled indicating that the horse is faster.
*I have confidence you can graph that*

5 0

2 years ago

). The molar mass of an organic acid, a compound composed of carbon, hydrogen, and oxygen, is 194.14 g/mol. Combustion of a 1.50

Nikitich [7]

Answer:

The empirical formula is C₆H₁₀O₇.

Step-by-step explanation:

1. Calculate the masses of C, H, and O from the masses given.

Mass of C = 2.0402 g CO₂ × (12.01 g C/44.01 g CO₂) = 0.5568 g C

Mass of H = 0.6955 g H₂O × (2.016 H/18.02 g H₂O) = 0.077 81 g H

Mass of O = Mass of compound - Mass of C - Mass of H = (1.500 – 0.5568 – 0.077 81) g = 0.8654 g O

=====

2. Convert these masses to moles.

Moles C = 0.5568 × 1/12.01 = 0.046 36

Moles H = 0.077 81 × 1/1.008 = 0.077 19

Moles O = 0.8654 × 1/16.00 = 0.054 09

=====

3. Find the molar ratios.

Moles C = 0.046 36/0.046 36 = 1

Moles H = 0.077 19/0.046 36 = 1.665

Moles O = 0.054 09/0.046 36 = 1.167

======

4. Multiply the ratios by a number to make them close to integers

C = 1 × 6 = 6

H = 1.665 × 6 = 9.991

O = 1.167 × 6 = 7.001

=====

5. Round the ratios to integers

C:H:O =6:10:7

=====

6. Write the empirical formula

The empirical formula is C₆H₁₀O₇.

=======

7. Calculate the empirical formula mass

C₆H₁₀O₇ = 6×12.01 + 10×1.008 + 7×16.00

C₆H₁₀O₇ = 72.01 + 10.08+ 112.0

C₆H₁₀O₇ = 194.09

=====

8. Divide the molecular mass by the empirical formula mass.

MM/EFM = 194.14/194.09 = 1.000 ≈ 1

=====

9. Determine the molecular formula

MF = (EF)ₙ = (C₆H₁₀O₇)₁ = C₆H₁₀O₇

7 0

2 years ago

Using the systematic approach for equilibrium problems, calculate the pH of 0.05 M HOCl. Ka= 3.0*10-8 Group of answer choices 3.

SVEN [57.7K]

Answer:

The pH is equal to 4.41

Explanation:

Since HClO is a weak acid, its dissociation in aqueous medium is:

HClO ⇄ ClO- + H+

start: 0.05 0 0

change -x +x +x

balance 0.05-x x x

As it is a weak acid it dissociates very little, in its ClO- and H + ions, so the change is negative, where x is a degree of dissociation.

the acidity constant when equilibrium is reached is equal to:

$Ka=\frac{[ClO-]*[H+]}{[HClO]}=\frac{x*x}{0.05-x}=3x10^{-8}$

The 0.05-x fraction can be approximated to 0.05, because the ionized fraction (x) is very small, therefore we have:

$3x10^{-8}=\frac{x^{2} }{0.05}$

clearing the x and calculating its value we have:

$x=3.87x10^{-5}=[H+]=[ClO-]$

the pH can be calculated by:

$pH=-log[H+]=-log[3.87x10^{-5}]=4.41$

7 0

3 years ago

Please can any one help me by answering this question!!+ignore my answer!,

den301095 [7]

I have posted the answetr in this picture.

8 0

2 years ago

Robert has pure samples of both D-ribose and D-arabinose, but he forgot to label them. He only has some nitric acid, the reagent

Sauron [17]

Answer:

Following are the responses to the given question:

Explanation:

Since HN03 is an oxidation substance D-ribose u.ith oxidized to form in rubric acid Ribose is chiral, but rubric acid is achiral because of its symmetry mirror level, Hence no infrared roster in the sample holder is observed.

Please find the attached file.

D-Arabinose, on either hand, gives optical aldaric acid with such a net optical rotation observed inside the polarimeter for diagnosis with HN03.

4 0

2 years ago