1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
NeX [460]
2 years ago
6

Whose work is credited with being the beginning of the modern atomic theory​

Chemistry
1 answer:
Damm [24]2 years ago
7 0
Democritus (460-370 BC) was a Greek philosopher who theorized that all matter could be reduced to particles that could not be divided, which he described as “atomos.”

John Dalton (1766-1844) Proposed the atomic theory.

You might be interested in
The following exothermic reaction is allowed to reach equilibrium. What
Anon25 [30]
The answer is gonna be the last one :)
5 0
2 years ago
List three factors thatinfluence the rate at whick dissolving occurs
lys-0071 [83]
1) Temperature (heat) of the solution
2) Concentration (amount) of both solvent (usually water) and solute (substance being dissolved by solvent)
3) Movement (kinetic energy) of the solution, as in shaking/stirring
5 0
2 years ago
A) Find the gas speed of sulfur dioxide at 100.0 degrees Celsius? ______________
gtnhenbr [62]

a. 381.27 m/s

b. the rate of effusion of sulfur dioxide = 2.5 faster than nitrogen triiodide

<h3>Further explanation</h3>

Given

T = 100 + 273 = 373 K

Required

a. the gas speedi

b. The rate of effusion comparison

Solution

a.

Average velocities of gases can be expressed as root-mean-square averages. (V rms)  

\large {\boxed {\bold {v_ {rms} = \sqrt {\dfrac {3RT} {Mm}}}}

R = gas constant, T = temperature, Mm = molar mass of the gas particles  

From the question  

R = 8,314 J / mol K  

T = temperature  

Mm = molar mass, kg / mol  

Molar mass of Sulfur dioxide = 64 g/mol = 0.064 kg/mol

\tt v=\sqrt{\dfrac{3\times 8.314\times 373}{0.064} }\\\\v=381.27~m/s

b. the effusion rates of two gases = the square root of the inverse of their molar masses:  

\rm \dfrac{r_1}{r_2}=\sqrt{\dfrac{M_2}{M_1} }

M₁ = molar mass sulfur dioxide = 64

M₂ =  molar mass nitrogen triodide = 395

\tt \dfrac{r_1}{r_2}=\sqrt{\dfrac{395}{64} }=\dfrac{20}{8}=2.5

the rate of effusion of sulfur dioxide = 2.5 faster than nitrogen triodide

4 0
2 years ago
What is the ratio of [a–]/[ha] at ph 2.75? the pka of formic acid (methanoic acid, h–cooh) is 3.75?
Varvara68 [4.7K]

The dissociation of formic acid is:

HCOOH \rightleftharpoons HCOO^{-} + H^{+}

The acid dissociation constant of formic acid, k_a is:

k_a = \frac{[HCOO^{-}]  [H^{+}]}{HCOOH}

Rearranging the equation:

\frac{[HCOO^{-}]}{[HCOOH]} = \frac{k_a}{[H_+]}

pH = 2.75

pH = -log[H^{+}]

[H^{+}]= 10^{-2.75} = 1.78 \times 10^{-3}

pk_a = 3.75

k_a = 10^{-3.75} = 1.78\times 10^{-4}

Substituting the values in the equation:

\frac{[HCOO^{-}]}{[HCOOH]} = \frac{k_a}{[H_+]}

\frac{[HCOO^{-}]}{[HCOOH]} = \frac{1.78\times 10^{-4}}{1.78\times 10^{-3}}

Hence, the ratio is \frac{1}{10}.

4 0
3 years ago
Choose the solvent below that would show the greatest freezing point lowering when used to make a 0.20 m nonelectrolyte solution
tatiyna

Answer : Carbon tetrachloride, k_f=29.9^oC/m will show the greatest freezing point lowering.

Explanation :

For non-electrolyte solution, the formula used for lowering in freezing point is,

\Delta T_f=k_f\times m

where,

\Delta T_f = lowering in freezing point

k_f = molal depression constant

m = molality

As per question, the molality is same for all the non-electrolyte solution. So, the lowering in freezing point is depend on the k_f only.

That means the higher the value of k_f, the higher will be the freezing point lowering.

From the given non-electrolyte solutions, the value of k_f of carbon tetrachloride is higher than the other solutions.

Therefore, Carbon tetrachloride, k_f=29.9^oC/m will show the greatest freezing point lowering.

4 0
3 years ago
Other questions:
  • 16.34 g of CuSO4 dissolved in water giving out 55.51 kJ and 25.17 g CuSO4•5H2O absorbs 95.31 kJ. From the following reaction cyc
    10·1 answer
  • Give the number of significant figures 0.025
    15·1 answer
  • Who is john dalton,jj Thompson and ernest Rutherford ​
    5·1 answer
  • A scientist is studying two types of worms. Worm X has DNA identical to its parent. Worm Y has a combination of DNA from two par
    9·2 answers
  • Give one example of frequency which an elephant can hear but which a tiger cannot hear include a unit in ansawer
    5·1 answer
  • What is the solution to the problem expressed to he correct number of significant figures? 12.0/7.11
    15·1 answer
  • Which of the following is the correct chemical formula for cs and br? csbr cs2br csbr2
    10·2 answers
  • A substance has a melting point of °C. Tom says the substance is liquid at 20 ° C. Ben says it could be liquid or gas. Explain w
    6·2 answers
  • .
    5·2 answers
  • A compound formed with potassium and bromine that can detect blood in a stain by reacting with it to form distinctive crystals
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!