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3 years ago

Please help!!!!!!!!!!!

Chemistry

1 answer:

Butoxors [25]3 years ago

6 0

Answer:

I think it is B

Explanation:

Both prokaryotes and eukaryotes have all of those things except for organelles, which only eukaryotes have (also prokaryotes are smaller not eukaryotes)

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this is liquid water in the form of droplets that have condoned from atmospheric water vapor and than precipitated

svetlana [45]

I think it’s rain???

6 0

3 years ago

How many moles is 17.6 g NaOH?

Lynna [10]

Answer:

$\boxed {\boxed {\sf D. 0.440 \ mol \ NaOH}}$

Explanation:

To convert from moles to grams, the molar mass is used (mass of 1 mole). The values are the same as the atomic masses on the Periodic Table, but the units are grams per mole (g/mol) instead of atomic mass units.

<h3>1. Molar Mass</h3>

We are given the compound sodium hydroxide (NaOH) and we need to look up the molar masses of the individual elements.

Na: 22.9897693 g/mol
O: 15.999 g/mol
H: 1.008 g/mol

The formula for the compound has no subscripts, so there is 1 mole of each element in 1 mole of the substance. We can simply add the molar masses.

NaOH: 22.9897693 + 15.999 + 1.008 = 39.9967693 g/mol

This means there are 39.9967693 grams of sodium hydroxide in 1 mole.

<h3>2. Convert Grams to Moles </h3>

Use the molar mass we found as a ratio.

$\frac {39.9967693 \ g \ NaOH}{ 1 \ mol \ NaOH}$

Since we are converting 17.6 grams of NaOH to moles, we multiply by this value.

$17.6 \ g\ NaOH *\frac {39.9967693 \ g \ NaOH}{ 1 \ mol \ NaOH}$

Flip the ratio so the units of grams of NaOH cancel.

$17.6 \ g\ NaOH *\frac {1 \ mol \ NaOH}{ 39.9967693 \ g \ NaOH}$

$17.6 *\frac {1 \ mol \ NaOH}{ 39.9967693}$

$\frac{17.6 }{ 39.9967693} \ mol \ NaOH$

$0.4400355406 \ mol \ NaOH$

<h3>3. Round </h3>

The original measurement of grams has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.

0.4400355406

The 0 in the ten thousandths place (in bold above) tells us to leave the 0 in the thousandth place.

$0.440 \ mol \ NaOH$

17.6 grams of sodium hydroxide are equal to <u>0.440 moles of sodium hydroxide.</u>

3 0

3 years ago

Calculate the energy required to ionize a ground state hydrogen atom. report your answer in kilojoules.

hjlf

First we find for the wavelength of the photon released due to change in energy level. We use the Rydberg equation:

1/ʎ = R [1/n1^2 – 1/n2^2]

where,

ʎ is the wavelength

R is the rydbergs constant = 1.097×10^7 m^-1

n1 is the 1st energy level = 1

n2 is the higher energy level = infinity, so 1/n2 = 0

Calculating for ʎ:

1/ʎ = 1.097×10^7 m^-1 * [1/1^2 – 0]

ʎ = 9.1158 x 10^-8 m

Then calculate the energy using Plancks equation:

E = hc/ʎ

where,

h is plancks constant = 6.626×10^−34 J s

c is speed of light = 3x10^8 m/s

E = (6.626×10^−34 J s * 3x10^8 m/s) / 9.1158 x 10^-8 m

E = 2.18 x 10^-18 J = 2.18 x 10^-21 kJ

This is still per atom, so multiply by Avogadros number = 6.022 x 10^23 atoms / mol:

E = (2.18 x 10^-21 kJ / atom) * (6.022 x 10^23 atoms / mol)

E = 1312 kJ/mol

3 0

3 years ago

Darryl finds a bottle of what looks like clear water, with dirt settled at the bottom. When he shakes the bottle, the water gets

Mazyrski [523]

Answer: The correct answer is Heterogeneous mixture

Explanation:

Heterogeneous mixture are those mixture in which:

Substance is distributed in non uniform manner.
Two distinct layers are formed

Thus when water and dirt are mixed together it results in the formation of a heterogeneous mixture and after sometimes two different layers will be observed.

Hence, in the bottle there is a heterogeneous mixture of water and dirt.

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3 years ago

A weather map is an example of a

arlik [135]

C. Model. It's a graphical model that displays one or more weather elements.

5 0

3 years ago

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