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3 years ago

What was John Dalton's contribution to the development of the atomic theory?

Chemistry

1 answer:

Tpy6a [65]3 years ago

3 0

Answer:

<h3>A. Dalton recognized that tiny atoms combined to form complex structures. </h3>

You might be interested in

What are two foods that have acid in them

Ann [662]

There are a bunch of different types of foods that have acid in them, which can cause acid reflex or heartburn.

Some foods that have acid in them are:

Soft drinks (Caffeine, Cola...)
Sugar (which is in most of the food we eat nowadays)
Processed food (such as turkey, beef..)

8 0

3 years ago

An organic acid is composed of carbon (45.45%), hydrogen (6.12%), and oxygen (48.44%). Its molar mass is 132.12 g/mol. Determine

Andreas93 [3]

Answer:

C4H8O4

Explanation:

To determine the molecular formula, first, let us obtain the empirical formula. This is illustrated below:

From the question given, we obtained the following information:

C = 45.45%

H = 6.12%

O = 48.44%

Divide the above by their molar mass

C = 45.45/12 = 3.7875

H = 6.12/1 = 6.12

O = 48.44/16 = 3.0275

Divide by the smallest

C = 3.7875/3.0275 = 1

H = 6.12/3.0275 = 2

O = 3.0275/3.0275 = 1

The empirical formula is CH2O

The molecular formula is given by [CH2O]n

[CH2O]n = 132.12

[12 + (2x1) + 16]n = 132.12

30n = 132.12

Divide both side by the coefficient of n i.e 30

n = 132.12/30 = 4

The molecular formula is [CH2O]n = [CH2O]4 = C4H8O4

7 0

3 years ago

Read 2 more answers

As an FDA physiologist, you need 0.625 L of phosphoric acid acid / dihydrogen phosphate (H3PO4 (aq) / H2PO4 - (aq) ) buffer with

aksik [14]

Answer:

0.4058L of 1.0M H3PO4

0.2192L of 1.5M NaOH

Explanation:

The pKa of the H3PO4 / H2PO4- buffer is 2.12

To solve this question we must use H-H equation for this system:

pH = pKa + log [H2PO4-] / [H3PO4]

2.75 = 2.12 + log [H2PO4-] / [H3PO4]

0.63 = log [H2PO4-] / [H3PO4]

Where [] could be taken as the moles of each reactant

As you have H3PO4 solution, the reaction with NaOH is:

H3PO4 + NaOH → H2PO4- + Na+ + H2O

As you can see, both H3PO4 and H2PO4- comes from the same 1.0M H3PO4 solution

The moles of H3PO4 are:

[H3PO4] = Moles H3PO4 - Moles NaOH

And for H2PO4-:

[H2PO4-] = Moles NaOH added

Replacing in (1):

4.2658 = [Moles NaOH] / [Moles H3PO4 - Moles NaOH]

4.2658 Moles H3PO4 - 4.2658 moles NaOH = Moles NaOH

4.2658 Moles H3PO4 = 5.2658 moles NaOH <em>(1)</em>

In volume:

0.625L = Moles H3PO4 / 1.0M + Moles NaOH / 1.5M

0.625 = Mol H3PO4 + 0.6667 Moles NaOH <em>(2)</em>

Replacing (2) in (1):

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4 / 0.6667)

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4) / 0.6667

4.2658 Moles H3PO4 = 5.2658*(0.9375 - 1.5 mol H3PO4)

4.2658 Moles H3PO4 = 4.9367 -7.8983 mol H3PO4

12.1641 mol H3PO4 = 4.9367

Mol H3PO4 = 0.4058moles * (1L / 1.0moles) =

0.4058L of 1.0M H3PO4

And:

0.625L - 0.4058L =

0.2192L of 1.5M NaOH

5 0

3 years ago

For a concentration technique, Stotal is given as 19.31 ± 0.035, Smb is 0.22 ± 0.008, and kA is 0.154 ± 0.007 ppm–1, where Stota

professor190 [17]

Answer:

Explanation:

8 0

3 years ago

Which temperatures originally represented the fixed points<br> Celsius temperature scale?

frez [133]

Answer:Since 1743 the Celsius scale has been based on 0 °C for the freezing point of water and 100 °C for the boiling point of water at 1 atm pressure. Prior to 1743 the values were reversed (i.e. the boiling point was 0 degrees and the freezing point was 100 degrees).

Explanation: i no it

8 0

3 years ago