Which group on the periodic table contains elements in all 3 states of matter?

labwork [276]

Oh ok just wait a minute

7 0

3 years ago

In the laboratory you are asked to make a 0.565 m sodium bromide solution using 315 grams of water. How many grams of sodium bro

Scorpion4ik [409]

Answer : The mass of sodium bromide added should be, 18.3 grams.

Explanation :

Molality : It is defined as the number of moles of solute present in kilograms of solvent.

Formula used :

$Molality=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent}}$

Solute is, NaBr and solvent is, water.

Given:

Molality of NaBr = 0.565 mol/kg

Molar mass of NaBr = 103 g/mole

Mass of water = 315 g

Now put all the given values in the above formula, we get:

$0.565mol/kg=\frac{\text{Mass of NaBr}\times 1000}{103g/mole\times 315g}$

$\text{Mass of NaBr}=18.3g$

Thus, the mass of sodium bromide added should be, 18.3 grams.

6 0

3 years ago

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.

AlekseyPX

Answer:

The pH value of the mixture will be 7.00

Explanation:

Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.

Placing all the given data we obtain,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

5 0

3 years ago

Describe each of the following as a physical or chemical property.

lidiya [134]

Explanation:

Physical change -

It refers to any change during any process , where there is no new substance is formed , is referred to as a physical change.

Any change in the state of matter is characterised under physical change.

Chemical change -

It refers to any change in a chemical process , where there is formation of any new substance , is referred to as a chemical change .

From the options given in the question,

1. Apple turning brown , on air exposure , is an example of chemical change .

2. The physical state of mercury is liquid , is an example of physical change .

3. phosphorus burns on exposed to air , is an example of chemical change .

4. The gas Neon is colorless at the room temperature , is is an example of physical change .

7 0

3 years ago

in a given homologous series of hydrocarbons, the boiling point generally increases as the size of the molecules increases. the

vitfil [10]

The boiling point of hydrocarbons generally increases as the size of the molecules increases because more bonds are needs to be broken in larger organic molecules.

<h3>What are hydrocarbons?</h3>

Hydrocarbons are organic compounds which here composed of hydrogen and carbon alone.

Hydrocarbons are grouped into families or homologous series based on a reactive group known as the gincyiial group

The homologous series include

alkanes
alkenes
alkynes

The boiling point generally increases as the size of the molecules increases because more bonds are needs to be broken in larger organic molecules.

Learn more about hydrocarbons at: brainly.com/question/3551546

#SPJ1

5 0

2 years ago