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3 years ago

How did Mendeleev organize the elements to create a periodic table?

Chemistry

1 answer:

Nuetrik [128]3 years ago

3 0

According to increasing mass and number of protons

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1/ Which graph illustrates constant speed and velocity

Maksim231197 [3]

Velocity is said to be constant if its magnitude as well direction at any instant is remains the same. In D, if you draw a line parallel to y-axis at any time t, you can see that velocity is same. Hence, D is the correct graph.

The kinetic energy of gaseous molecules is greater than that of liquid molecules. Therefore, in gas, kinetic energy overcomes the force of attraction between molecules. In short, in gas phase, particles move at high speed and hence they have less force of attraction. In case of liquid phase, particles are close enough as a result there is much more force of attraction compared to gaseous molecules. In liquid state, kinetic energy cannot overcome force of attraction therefore, liquid molecules slow down.

Therefore, B is the correct answer.

4 0

4 years ago

Dry air can be liquified at temperatures below 78.8K. This material is an

Vlad1618 [11]

<h2>Answer : </h2>

<h3>D. HETEROGENEOUS MIXTURE </h3>

HOPE IT HELP ❤️

7 0

3 years ago

Plz help! I will give five star thanks and I will give brainliest

Harman [31]

Answer:

Conduction

Explanation:

Conduction is the transfer of heat energy from one substance to another or within a substance.

5 0

4 years ago

A 0.15 m solution of chloroacetic acid has a ph of 1.86. What is the value of ka for this acid?

dem82 [27]

Answer: $1.67\times 10^{-3}$

Explanation:

$ClCH_2COOH\rightarrow ClCH_2COO^-+H^+$

cM 0 0

$c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Given: c = 0.15 M

pH = 1.86

$K_a$ = ?

Putting in the values we get:

Also $pH=-log[H^+]$

$1.86=-log[H^+]$

$[H^+]=0.01$

$[H^+]=c\times \alpha$

$0.01=0.15\times \alpha$

$\alpha=0.06$

As $[H^+]=[ClCH_2COO^-]=0.01$

$K_a=\frac{(0.01)^2}{(0.15-0.15\times 0.06)}$

$K_a=1.67\times 10^{-3]$

Thus the vale of $K_a$ for the acid is $1.67\times 10^{-3}$

4 0

3 years ago

An aqueous solution is found to be 3.64% potassium nitrate by mass, how many grams of solution should I evaporate the water from

Sidana [21]

Answer:

513.74 g of solution

Explanation:

% Mass grams are defined as the <em>grams that are dissolved in salt</em> (in this case, it would be <em>potassium nitrate</em>) <em>dissolved every 100 g of the solution</em>. Having this information, you can calculate the amount of solution that has dissolved 18.7 g of potassium nitrate, which is what we want to obtain.

The relationship is:

3.64 g of potassium nitrate _____ 100 g solution

18.7 g of potassium nitrate _____ X = 513.74 g of solution

Calculation: 18.7g x 100g / 3.64g = 513.74 g of solution

So, <em>I need 513.74 g of solution to get 18.7g of potassium nitrate by evaporating it</em>.

8 0

3 years ago