Rachel was riding her bike at a velocity of 9 m/s to the east. Her velocity

Is mixing salt and pepper physical change or chemical change ?

Rom4ik [11]

Yes mixing salt with pepper change

6 0

3 years ago

6 CO 2 + 12 H 2 O C 6 H 12 O 6 + 6 H 2 O + 6 O 2

adelina 88 [10]

During photosynthesis plant release
<span>C 6 H 12 O 6 + 6 H 2 O + 6 O 2
the gas is 6O2
</span>

3 0

3 years ago

If the trend in a property is periodic, it means it will

kotegsom [21]

Answer:

d) repeat

Explanation:

If the trend in a property is periodic, it means it will repeat on the periodic table.

Periodic properties on the table have a constant pattern as we move up or down a group or across a period from left to right.

This helps to predict some of the salient properties of elements as we move through the periodic table.
For example, on most periodic groups, metallicity increases as we move down the group and it decreases across the period.

8 0

3 years ago

What is the chemical structure of coal?<br>What is the molecular weight of coal?

nydimaria [60]

1) As for its chemical composition, coal is a mixture of high-molecular-weight polycyclic aromatic compounds, such as benzene C6H6, toluene C6H5CH3, xylene C6H4(CH3)2, naphthalene C10H8, anthracene C14H10, pyrene C16H10 and their derivatives with high mass fraction of carbon, as well as of water and volatile substances.

2) The coal asphaltenes have a relatively narrow MWD (full width ≈ 150 amu) with an average molecular weight of ≈340 amu. The petroleum asphaltenes display a broader MWD (full width ≈ 300 amu) and are heavier on average (≈680 amu).

~ I hope this helped, and I would appreciate Brainliest. ♡ ~ ( I request this to all the lengthy answers I give ! )

4 0

3 years ago

In a 66.0-g aqueous solution of methanol, CH 4 O , CH4O, the mole fraction of methanol is 0.300. 0.300. What is the mass of each

Mumz [18]

Answer:

The solution is composed by 37.5 g of water and 28.5 g of methanol.

Explanation:

Total mass = 66 g

Mole fraction methanol: 0.3

Sum of mole fraction = 1

Therefore, mole fraction of water = 0.7

Let's find out the mass of each component by this two equations:

Methanol mass + Water mass = 66 g

Water mass = 66g - Methanol mass

Methanol mass = 66g - water mass

water mass / 18 g/mol = moles of water

methanol mass / 32 g/mol = moles of methanol

moles of water / total moles = 0.7

moles of methanol / total moles = 0.3

water mass / 18 g/mol / (water mass / 18 g/mol) + (methanol mass / 32 g/mol) = 0.7 ; let's replace methanol mass, as (66 - water mass)

water mass / 18 g/mol / (water mass / 18 g/mol) + (66 - water mass / 32 g/mol) = 0.7 → The unknown is water mass (X)

X / 18 / ( (X / 18) + ((66-X) / 32)) = 0.7

(X / 18) + ((66-X) / 32) = (16X + 594 - 9X)/288

X / 18 / (16X + 594 - 9X)/288 = 0.7

X/18 = 0.7 . ( (7X + 594 ) / 288)

X / 18 = 7/2880 ( 7X + 594)

X = 7/2880 ( 7X + 594) 18

X = 7/160 (7X + 594)

X = 49/160X + 2079/80

X - 49/160X = 2079/80

111/160X = 2079/80

X = 2079/80 . 160/111 = 37.5 g → mass of water

Therefore, mass of methanol → 66 g - 37.4 g = 28.5 g

7 0

3 years ago