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2 years ago

Question 11 of 32

Chemistry

2 answers:

aev [14]2 years ago

6 0

Answer:

Explanation:

They form hypothesis first, then perform the experiment to test the hypothesis. After multiple experiments, they form a theory.

Thus C is correct

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rjkz [21]2 years ago

5 0

Answer:

Explanation:

a hypothesis always comes first

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Identify fossil types match each each type of fossil to its description

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Well we need to see the fossil

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3 years ago

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Additional solute is added to a saturated solution of a solid and a liquid after being heated above room temperature. Once no mo

PSYCHO15rus [73]

Answer:

After the solution is heated, but before additional solute is added

Explanation:

An unsaturated solution is a solution that contains less solute than it can normally hold at a given temperature. Hence an unsaturated solution can still dissolve more solute.

When the solution is heated, the saturated cold solution becomes an unsaturated hot solution which is capable of dissolving more solute at this point.

Once more solute is dissolved, the solution becomes saturated again just before it begins to cool since no more solute dissolves in the solution at some point before cooling and addition of seed crystals.

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3 years ago

A compound with molecular formula C6H15N exhibits a singlet at d 0.9 ppm (1H), a triplet at 1.10 ppm (3H), a singlet at 1.15 ppm

Triss [41]

Answer:

CH3 - CH2 - NH - C(CH3)3

Explanation:

The 1HNMR is the acronym for Proton nuclear magnetic resonance and it is used in chemistry or Chemical laboratory for the analysis and identification of compounds.

In order to be able to answer the question accurately you have to have the tables containing all the values for chemical shift. The Chemical shift is measured in ppm and it occur due to Resonance frequency variation.

From the table, a singlet at 1.15 ppm (9H) is - C(CH3)3.

A singlet at d 0.9 ppm (1H) shows the presence of a secondary amine group, that is -R2NH group.

A triplet at 1.10 ppm (3H) shows that we have;

CH3- CH2-

A quartet at 2.6 ppm (2H) shows that we have;

-CH2 - CH3.

Therefore, joining all together we have;

CH3 - CH2 - NH - C(CH3)3.

Kindly check attached file for the picture of the structure.

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3 years ago

The name of Earth's single, huge continent from over 250 million years ago is (1 point)

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3 years ago

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If a proton and an electron are released when they are 5.50×10−10 mm apart (typical atomic distances), find the initial accelera

Vlada [557]

Answer: The initial acceleration of the proton = (4.56 × 10^23) m/s2

The initial acceleration of the electron = (8.36 × 10^26) m/s2

Explanation: The force of attraction between the proton and electron can be computed using the statements of Coulomb's law which state that the force of attraction between two charged particles is directly proportional to the product of the two charges and inversely proportional to the square of their distances apart.

F = (Kq1q2)/(r^2) where K = (9 × (10^9) Nm(C^-2))

But q1 is the charge on a proton = (1.6 × (10^-19)) C

q2 is charge on an electron = -(1.6 × (10^-19)) C

r = (5.50 × (10^-10))mm = (5.50 × (10^-13))m

Computing all that, F = 0.0007616529 N = (7.62 × 10^-4) N

But the force of attraction is converted to that required for motion when they're released.

F = ma.

For proton, m = (1.67 × 10^-27) kg

a = F/m = 0.000762/(1.67 × 10^-27) = (4.56 × 10^23) m/s2

For electron, m = (9.11 × 10^-31) kg

a = F/m = 0.000762/(9.11 × 10^-31) = (8.36 × 10^26) m/s2

QED!

7 0

3 years ago