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4 years ago

Which is a correct comparison between the modern quantum model and John Dalton’s model of the atom?

Chemistry

2 answers:

Greeley [361]4 years ago

4 0

Answer:

The modern model recognizes particles in the atom, whereas Dalton’s model does not.

Explanation:

The modern model considers the atom to consist of electrons, protons, and neutrons.

A is wrong. The modern model of the atom is widely accepted.

B is wrong. Dalton assumed that all atoms are identical. The modern model recognizes that there are isotopes of atoms.

D is wrong. The modern model explains emission spectra. Dalton's model does not.

inessss [21]4 years ago

3 0

Answer:

Explanation:

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How do you measure the mass of a liquid?

garri49 [273]

Answer:Mathematically: D = m/v. If you know what liquid you have, you can look up its density in a table. Once you know that, all you have to do to find the mass of the liquid is to measure its volume. Once you know density and volume, calculate mass using this relationship: mass = density • volume.

Explanation:

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3 years ago

The type of chemical reaction represented by the following equation is...

natali 33 [55]

Answer:

A) Decomposition

Explanation:

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2 years ago

What is the maximum number of grams of N-acetyl-p-toluidine can be prepared from 70. milliliters of 0.167 M p-toluidine hydrochl

Genrish500 [490]

<u>Answer:</u> The maximum amount of N-acetyl-p-toluidine that can be prepared is 1.7 grams.

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$

Molarity of p-toluidine hydrochloride solution = 0.167 M

Volume of solution = 70. mL

Putting values in above equation, we get:

$0.167M=\frac{\text{Moles of p-toluidine hydrochloride}\times 1000}{70}\\\\\text{Moles of p-toluidine hydrochloride}=\frac{0.167\times 70}{1000}=0.0117mol$

The chemical equation for the reaction of p-toluidine hydrochloride and acetic anhydride follows:

$\text{p-toluidine hydrochloride}+\text{Acetic anhydride}\rightarrow \text{N-acetyl-p-toluidine}$

By Stoichiometry of the reaction:

1 mole of p-toluidine hydrochloride produces 1 mole of N-acetyl-p-toluidine

So, 0.0117 moles of p-toluidine hydrochloride will produce = $\frac{1}{1}\times 0.0117=0.0117mol$ of N-acetyl-p-toluidine

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of N-acetyl-p-toluidine = 149.2 g/mol

Moles of N-acetyl-p-toluidine = 0.0117 moles

Putting values in equation 1, we get:

$0.0117mol=\frac{\text{Mass of N-acetyl-p-toluidine}}{149.2g/mol}\\\\\text{Mass of N-acetyl-p-toluidine}=(0.0117g/mol\times 149.2)=1.7g$

Hence, the maximum amount of N-acetyl-p-toluidine that can be prepared is 1.7 grams.

6 0

4 years ago

The solubility of a sample will ____________ when the size of the sample increases.

devlian [24]

The solubility of a sample will decrease when the size of the sample increases.

When the Size of sample is bigger, it means there is more particles that make up that sample so the amount of solvent to dissolve the sample will also be in the greater amount. Thus, when the sample size increases the solubility decrease. We can also say that size of sample and solubility are inversely proportional to each other.

8 0

3 years ago

Why do we need to have common denominators when adding fractions?

jeyben [28]

So that we have the right answer once we do the addition
Say that I measure my self at 12 feet with one measuring stick, and go on with another measuring stick that tells me I'm 3 meters tall, if I added those, I would be at something like 15/46 or something like that. See that would be wrong. We would want the right denominator so that it could be easier and also correct.

3 0

3 years ago