Which substance combines with iron in the presence of water to form rust?

lina2011 [118]

Answer:

The warmer, lighter air rises, bringing cooler, heavier air to low altitudes.

Air at higher altitudes doesn't have as much air weighing down on it from above.

Explanation:

In short - air pressure is the result of the cumulative force that air molecules act on objects below them due to Earth's gravity. The higher the altitude, the less air molecules there are to act a force below them, and therefore, there's less air pressure at higher altitudes.

7 0

2 years ago

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In the partition coefficient experiment 4A this week, after thorough mixing of the reagents, phase separation will occur. The to

Andreas93 [3]

Answer:

The top layer is the Aqueous layer, and the benzoic acid is contained in the non-aqueous layer/oil phase.

Explanation:

A separating funnel is a very important piece of laboratory glassware that is used to separate the components of liquid-liquid mixtures which are immiscible. This technique is used in the extraction of the components of mixtures.

The liquids separate into two phases. The separation is based on the differences in the liquids' densities, where the denser liquid settles below and the lower density liquid stays afloat. Liquids used for this kind of separation are usually different liquids, one is the aqueous layer and the other, a non-aqueous layer.

Partition coefficient or distribution coefficient is defined as the ratio of the concentrations of a compound in two immiscible solvents at equilibrium.

Organic solvents (except halogenated organic compounds) with densities greater than that of water i.e 1g/mL ( usually called the oil phase) settle at the bottom of the aqueous phase.

Benzoic acid. will settle at the bottom layer ( i.e the lower phase).

7 0

3 years ago

Recycling one ton of paper is the equivalent of approximately how much of the following? a.) all of the below b.) 460 gallons of

jek_recluse [69]

I think the answer is a

5 0

3 years ago

Many double-displacement reactions are enzyme-catalyzed via the "ping pong" mechanism, so called because the reactants appear to

zhenek [66]

Answer:

D. It will decrease by a factor of 4

Explanation:

According to the question , the equation follows :

$A+B\rightarrow C+D$

Rate law : This states the rate of reaction is directly proportional to concentration of reactants with each reactant raised to some power which may or may not be equal to the stoichiometeric coefficient.

$Rate\ \alpha [A]^{a}[B]^{b}$

$r=[A]^{a}[B]^{b}$ .................(1)

STEP": First, find out the power "a" and "b"

a+b = 3 (because it is given that the reaction follow 3rd order-kinetics)

According to question, doubling the concentration of the first reactant causes the rate to increase by a factor of 2 means,

r' = 2r if [A'] = 2[A]

Here [B] is uneffected means [B']=[B]

hence new rate =

$r'=[A']^{a}[B']^{b}$

Put the value of [A'] , [B'] and r' in the above equation:

$2r=[2A]^{a}[B]^{b}$ ...........(2)

Divide equation (1) by (2) we , get

$\frac{2r}{r}=\frac{[2A]^{2}[B]^{b}}{[A]^{a}[B]^{b}}$

$2= 2(\frac{A}{A})^{a}\times (\frac{B}{B})^{b}$

Here A and A cancel each other

B and B cancel each other

We get,

$2= 2^{a}\times 1^{b}$

1^b = 1 ( power of 1 = 1)

$2= 2^{a}$

This is possible only when a = 1

We know that : a + b = 3

1 + b = 3

b =3 -1 = 2

b = 2

Hence the rate law becomes :

$r=[A]^{a}[B]^{b}$

$r=[A]^{1}[B]^{2}$ .............(3)

Look in the question now, it is asked to calculate the concentration of [B],if cut in half

Hence

[B']=1/2[B]

Insert the value of [B'] in equation (3)

$r'=[A]^{1}[B']^{2}$

$r'=[A]^{1}(\frac{1}{2}[B])^{2}$

$r'=\frac{1}{4}[A]^{1}[B]^{2}$ ............(a)

But

$r=[A]^{a}[B]^{b}$ ..............(b)

Compare equation (a) and (b) , we get

new rate r' =

r' = 1/4 r

7 0

3 years ago

How can I tell how many electrons in each energy level? When my question states "third sublevel" does this mean sublevel P?

nikitadnepr [17]

Sorry for the delay! My internet is a bit bad.
P is the third sublevel. Each sublevel (the angular momentum quantum number), has its own number:
s = 1, p =3, d = 5, f = 7
The number of electrons for each is:
s-2
p-6
d-10
f-14
It's easier to just memorize these numbers, but the equation for determining the sublevel number is 2n (n = the principal quantum number). The principal quantum number is based on the period the element is in.

6 0

3 years ago