I NEED HELP!!!!!!!!!!!!!!!!

Mass box A = 10 grams; Mass box B = 5 grams; Mass box C—made of one A and one B How many boxes of B would be required to make 30

Iteru [2.4K]

Mass box C is 10+5. (So C is 15)

But if C was 30, how many times could you put B (5) into it?

30/5 = 6

You would need 6 boxes of B to make 30 grams of C.

5 0

3 years ago

Read 2 more answers

What is the charge of oxygen in Na2O?

Nuetrik [128]

In Na2O, what is the oxidation state of oxygen? In Na2O oxidation state of Na is 1+

3 0

3 years ago

Read 2 more answers

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

Which is NOT a property of gold?

earnstyle [38]

Answer:

A

Explanation:

5 0

4 years ago

Which of the following is an example of ionic compound?

spayn [35]

What you are looking for is something from the left side of the periodic table (the metals), combined with something from the right side of the periodic table.

SiCl4 is something from the middle with something on the right. Not the answer.

HCl is a possible answer, but it is not the best one, because Hydrogen can be on both sides. It is not quite as willing to give up its electrons as the answer.

CCl4 has the same problem as A.

The answer is C

Ca is in column 2 just about as far left as you can get.

Cl is in column 17 which is just about as far right as you can get.

5 0

3 years ago