Julie was working on homework and was asked to name the formula, SnS2. She wrote down

How does ur body maintain constant tempature on a hot day?

Lina20 [59]

It knows that when water evaporates, it carries heat energy away with it.
So your body puts some water out on your skin, and hopes that it will
evaporate. We call that "perspiring" or "sweating".

8 0

3 years ago

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Conservation of Mass means:

Anarel [89]

Answer:

Conservation of mass mean mass cannot be created nor destroyed

Explanation:

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3 years ago

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Calculate the pH of: (a) 0.1M HCl; (b) 0.1M NaOH; (c) 3 X 10% M HNO3; (d) 5 X 10-10 M HCIO.; and (e) 2 x 10-8 M KOH.

Shtirlitz [24]

Answer:

(a) $pH = -Log (0.1M) = 1$

(b) $pH = -Log (10^{-13}M) = 13$

(c) $pH = -Log (3x10^{-3}M) = 2.5$

(d) $pH = -Log (4.93x10^{-10}M) = 9.3$

(e) $pH = -Log (5^{-7}M) = 6.3$

Explanation:

To calculate de pH of an acid solution the formula is:

$pH = -Log ([H^{+}]) = 1$

were [H^{+}] is the concentration of protons of the solution. Therefore it is necessary to know the concentration of the protons for every solution in order to solve the problem.

(a) and (c) are strong acids so they dissociate completely in aqueous solution. Thus, the concentration of the acid is the same as the protons.

(b) and (e) are strong bases so they dissociate completely in aqueous solution too. Thus, the concentration of the base is the same as the oxydriles. But in this case it is necessary to consider the water autoionization to calculate the protons concentration:

$K_{w} =[H^{+} ][OH^{-}]=10^{-14}$

clearing the $[H^{+} ]$

$[H^{+} ]=\frac{10^{-14}}{[OH^{-}]}$

(d) is a weak base so it is necessary to solve the equilibrium first, knowing $Ka=3.24x10^{-8}$

The reaction is $HClO$ → $H^{+} + CO^{-}$ so the equilibrium is

$Ka=3.24x10^{-8}=\frac{x^{2}}{5x10^{-8}-x}$

clearing the <em>x</em>

${x^{2}={1.62x10^{-17}-3.24x10^{-8}x}$

$x=[H^{+}]=4.93x10^{-10}$

6 0

3 years ago

What is another name for a beta minus (β–) particle?

Vikki [24]

Answer: Another name for beta-minus particle is electron.

Explanation: Beta-minus particle $(_{-1}^0\beta )$ is released during the beta-minus decay nuclear reaction.

In this nuclear reaction, a neutron gets converted into proton and electron. The electron released is the beta-minus particle.

The charge on these particles is -1 and mass of these particles is negligible.

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3 years ago

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Explain why the quantum number set (3, 3, -2, +½) is not possible for an electron in a ground-state atom.

Solnce55 [7]

Answer:- It's not correct because the values of n and l are same.

Explanations:- The four quantum numbers are n, l, ml and ms where n stands for Principal quantum number and has values like 1, 2, 3 and so on.

l stands for azimuthal quantum number and has values from 0 to (n-1) where n is principal quantum number.

For the given set of quantum numbers, value of n is 3. So, the possible values of l would be 0,1 and 2.

The value of l for the given set of quantum numbers is 3 which is the reason why the given set is not possible.

5 0

3 years ago