How many significant figures in 5241.034?

When salt is dissolved in water the result is a

MrRissso [65]

Answer:

Water molecules pull the sodium and chloride ions apart

Explanation:

3 0

3 years ago

How do we know stars are element factories?

djverab [1.8K]

In a nutshell, stars are mainly made of hygrogen, element 1.

over time, elements got more dense as they collided and cooled, leading to other gases, metals...

then they explode, which lead to all kinds of further complex elements.

The stuff that makes up the universe a lot of it is from exploding star stuff, and the Earth was built up upon these remains and the atoms that make up organisms even could originally be from stars.

8 0

4 years ago

12. In a gas mixture consisting of carbon dioxide (CO2) and nitrogen (N2), the carbon dioxide molecules have a root-mean-square

zaharov [31]

Answer:

The correct answer is option e.

Explanation:

The formula used for root mean square speed is:

$\nu_{rms}=\sqrt{\frac{3kN_AT}{M}}$

where,

$\nu_{rms}$ = root mean square speed

k = Boltzmann’s constant = $1.38\times 10^{-23}J/K$

T = temperature

M = Molar mass

$N_A$ = Avogadro’s number = $6.02\times 10^{23}mol^{-1}$

Root mean square speed of carbon dioxide molecule:

$\nu_{rms}= 550 m/s$

Temperature of the mixture = T =?

Molar mass of carbon dioxide = 44 g/mol = 0.044 kg/mol

$\nu_{rms}=550 m/s=\sqrt{\frac{3\times 1.38\times 10^{-23}J/K\times 6.022\times 10^{23}mol^{-1}T}{0.044 kg/mol}}$

T = 533.87 K

Root mean square speed of nitrogen molecule:

$\nu'_{rms}= ?s$

Molar mass of nitrogen = 28 g/mol = 0.028 kg/mol

$\nu'_{rms}=\sqrt{\frac{3\times 1.38\times 10^{-23}J/K\times 6.022\times 10^{23}mol^{-1}\times 533.87 K}{0.028 kg/mol}}$

$\nu'_{rms}=689.46 m/s\approx 689 m/s$

689 m/s is the root-mean-square speed of the nitrogen molecules in the sample.

7 0

3 years ago

3. The relationship between two optical isomers is most like the relationship between _____.

Leona [35]

Answer: option D

Explanation:

Since optical isomers are of 2 types called Enantiomers and Diastereomers

Enantiomers are non super impossible mirror images to each other. Examples, a man's right and left hand, Gloves

Diastereomers are non super impossible non mirror images

6 0

3 years ago

For each of the following compounds, indicate the pH at which 50% of the compound will be in a form that possesses a charge and

Virty [35]

Answer:

a. 2..86 b. 4.86 c. 10.7 d. 8.7

Explanation:

a. Determine a pH at which 50% of ClCH2COOH will be in a form that possesses a charge.

Using the Henderson-Hasselbalch equation,

pH = pKa + log[A⁻]/[HA]

where [A⁻] = concentration of conjugate base (or charged form) and [HA] = concentration of acid.

At 50% concentration, [A⁻] = [HA] ⇒ [A⁻]/[HA] = 1

So, pH = pKa + log[A⁻]/[HA]

pH = pKa + log1

pH = pKa = 2.86

b. Determine a pH at which pH more than 99% of ClCH2COOH will be in a form that possesses a charge.

Let x be the concentration of the acid. Since 99% of it should possess a charge, the basic concentration is 0.99x while the acidic concentration is remaining 1 % (1 - 0.99)x = 0.01x

Using the Henderson-Hasselbalch equation,

pH = pKa + log[A⁻]/[HA] where [A⁻] = concentration of conjugate base (or charged form) = 0.99x and [HA] = concentration of acid = 0.01x.

pH = pKa + log0.99x/0.01x

pH = pKa + log0.99/0.01

pH = 2.86 + log99

pH = 2.86 + 1.996

pH = 4.856

pH ≅ 4.86

c. Determine a pH at which 50% of CH3CH2NH+3 will be in a form that possesses a charge.

Using the Henderson-Hasselbalch equation,

pH = pKa + log[A⁻]/[HA]

where [A⁻] = concentration of conjugate base and [HA] = concentration of acid.

At 50% concentration, [A⁻] = [HA] ⇒ [A⁻]/[HA] = 1

So, pH = pKa + log[A⁻]/[HA]

pH = pKa + log1

pH = pKa = 10.7

d. Determine a pH at which pH more than 99% of CH3CH2NH+3 will be in a form that possesses a charge.

Let x be the concentration of the acid. Since 99% of it should possess a charge, the basic concentration is 0.01x while the acidic concentration is remaining 99 % (1 - 0.01)x = 0.99x (which possesses the charge).

Using the Henderson-Hasselbalch equation,

pH = pKa + log[A⁻]/[HA] where [A⁻] = concentration of conjugate base = 0.01x and [HA] = concentration of acid = 0.99x.

pH = pKa + log0.01x/0.99x

pH = pKa + log1/99

pH = 10.7 - log99

pH = 10.7 - 1.996

pH = 8.704

pH ≅ 8.7

5 0

4 years ago