Determine which reaction has the highest activation energy.

Why did Dalton think it was important to use his system of symbols for the chemical elements?

77julia77 [94]

The answer is : A good luck :)

4 0

3 years ago

Read 2 more answers

Are there any parts of the human body that get oxygen directly from the air and not from the blood?

n200080 [17]

Answer: Cornea

Explanation: The cornea is the only part of a human body that has no blood supply as it gets oxygen directly through the air.

3 0

3 years ago

How many parts per million of fluoride in a solution that is 500 grams of fluoride and 500,000 liters water

erik [133]

0.000001‬ppm

Explanation:

Mass of fluoride = 500g

Volume of water = 500000liters

Unknown:

Parts per million of fluoride = ?

Solution:

The parts per million is the amount of solute in milligram dissolved in a liter of water or milligram per kilogram of solvent

It is a unit used to express very small concentration.

we need to convert g - mg

500g = 500 x 10⁻³mg = 0.5mg

Concentration in parts per million = $\frac{mass in mg}{Volume in liters}$

Concentration in parts per million = $\frac{0.5}{500000}$ = 0.000001‬ppm

learn more:

Parts per million brainly.com/question/2854033

#learnwithBrainly

7 0

3 years ago

Help please if its right i'll give brainiest

Mkey [24]

I believe it is spontaneous generation

5 0

2 years ago

28) Consider a 21.0 mL sample of pure lemon juice with a citric acid (H3C6H5O7) concentration of 0.30M. a. How many moles of cir

Damm [24]

<h3>#a. Answer:</h3>

0.0063 mole

<h3>Solution and explanation:</h3>

We are given 21.0 mL citric acid with a concentration of 0.30 M

Part a requires we calculate the number of moles of citric acid.

We need to know how to calculate the concentration of a solution;

Concentration or molarity = Number of moles ÷ Volume of the solution

Thus;

Number of moles = Concentration × Volume

Hence;

Moles = 0.30 M × 0.021 L

= 0.0063 mole

<h3>#b. Answer</h3>

1.21 g citric acid

<h3>Solution</h3>

Part B

We are required to calculate the mass of citric acid in the sample

Number of moles of a compound is calculated by dividing its mass by its molar mass.

Molar mass of Citric acid = 192.124 g/mol

Moles of citric acid = 0.0063 mole

But; Mass = Number of moles × Molar mass

Mass of citric acid = 0.0063 mol × 192.124 g/mol

= 1.21 g citric acid

<h3>#c. Answer</h3>

4.167 mL

<h3>Solution:</h3>

Part C

We are required to determine the initial volume before dilution;

We have;

Initial concentration (M1) = 0.30 M

Final volume (V2) = 250 mL or 0.25 L

Final concentration (M2) = 0.0050 M

Using the dilution formula we can get the initial volume;

Therefore, since; M1V1 =M2V2

V1 = M2V2÷M1

= (0.0050 × 0.25)÷ 0.30

= 0.004167 L or

= 4.167 mL

Therefore, the initial volume of the solution is 4.167 mL

8 0

3 years ago