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3 years ago

Ice cubes in water and explain why it is either a homogeneous or heterogeneous mixture.

1 answer:

5 0

Ice cubes are made of water which has undergone freezing, which made it into ice. Both ice cubes and water have the same properties. But in this case, when ice and water are mixed, it is considered a heterogeneous mixture and not homogeneous. Why? Going back to the definition of what a heterogeneous mixture is, this mixture shows a visible difference of difference phases or substances. In the ice and water mixture, it is obviously seen that ice is solid, and water is liquid.

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Debido a que propiedad un cuerpo flota en el agua y otro no

Nata [24]

Answer:

cuerpo flota o se hunde es su densidad con respecto a la del líquido en que se sumerge. En cambio, una nuez (densidad = 0.5) flotara en ambos líquidos mientras que una piedra (densidad = 2) se hundirá.

Explanation:

8 0

3 years ago

A set of headphones produces sounds that cancel out sound waves from the

Basile [38]

Answer:

C. Destructive interference

Explanation:

<em>Destructive interference</em> is when there are two waves <u>with the same frequency</u>, and the peaks of one wave (the highest points) line up with the valleys (the lowest points) of the second one.

Constructive interference would cause the sound to be louder.

Absorption and reflection are interactions that would not take into account the fact that the headphones produce sounds.

4 0

3 years ago

What is the pOH of a 0.150 M solution of potassium nitrite? (Ka HNO2 = 4.5 x 10−4 )

yanalaym [24]

Answer:

11.9 is the pOH of a 0.150 M solution of potassium nitrite.

Explanation:

Solution : Given,

Concentration (c) = 0.150 M

Acid dissociation constant = $k_a=4.5\times 10^{-4}$

The equilibrium reaction for dissociation of $HNO_2$ (weak acid) is,

$HNO_2+H_2O\rightleftharpoons NO_2^-+H_3O^+$

initially conc. c 0 0

At eqm. $c(1-\alpha)$ $c\alpha$ $c\alpha$

First we have to calculate the concentration of value of dissociation constant $(\alpha )$ .

Formula used :

$k_a=\frac{(c\alpha)(c\alpha)}{c(1-\alpha)}$

Now put all the given values in this formula ,we get the value of dissociation constant $(\alpha )$ .

$4.5\times 10^{-4}=\frac{(0.150\alpha)(0.150\alpha)}{0.150(1-\alpha)}$

$4.5\times 10^{-4} - 4.5\times 10^{-4}\alpha =0.150\alpha ^2$

$0.150\alpha ^2+4.5\times 10^{-4}\alpha-4.5\times 10^{-4}=0$

By solving the terms, we get

$\alpha=0.0533$

No we have to calculate the concentration of hydronium ion or hydrogen ion.

$[H^+]=c\alpha=0.150\times 0.0533=0.007995 M$

Now we have to calculate the pH.

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

$pH=-\log (0.007995 M)$

$pH=2.097\approx 2.1$

pH + pOH = 14

pOH =14 -2.1 = 11.9

Therefore, the pOH of the solution is 11.9

4 0

3 years ago

One difference between strong bases and weak bases is 1. strong bases can neutralize more acid than weak bases. 2. strong bases

Tema [17]

One difference between strong bases and weak bases is that a strong bases dissociate completely while weak bases do not. A strong base is a compound that completely ionizes into metal and hydroxide ions when in a solution, on the other hand weak bases only partially ionizes to metal and hydroxide ions in solution. An example of a weak base is ammonia and an example of a strong base is sodium hydroxide.

6 0

3 years ago

What material makes up ash and pumice?

slamgirl [31]

Pumice rocks are formed due to the air that is trapped in between the rocks, a body of magma spurting out with dissolved gas under pressure. As the magma cracks through the Earth’s surface, the sudden pressure drop causes the gas to come out of the solution. The flash of gas form the vent slices the magma and blows it out as a molten lather. The lather hastily solidifies as it flies into the air and falls back to Earth as pieces of pumice.

7 0

3 years ago