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3 years ago

Why do some metals loose their shine overtime but gold does not?

1 answer:

5 0

Becuase gold is very unreactive and does not react with oxygen whereas other metals do, therefore they tarnish and gold does not

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30cm^3 of a dilute solution of Ca(OH)2 required 11 cm^3 of 0.06 mol/dm^. Hcl for complete neutralization. Calculate the concentr

Alenkasestr [34]

Answer: Thus concentration of $Ca(OH)_2$ in $mol/dm^3$ is 0.011 and in $g/dm^3$ is 0.814

Explanation:

To calculate the concentration of $Ca(OH)_2$ , we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HCl$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is $Ca(OH)_2$

We are given:

$n_1=1\\M_1=0.06mol/dm^3\\V_1=11cm^3=0.011dm^3\\n_2=2\\M_2=?\\V_2=30cm^3=0.030dm^3$ $1cm^3=0.001dm^3$

Putting values in above equation, we get:

$1\times 0.06mol/dm^3\times 0.011dm^3=2\times M_2\times 0.030dm^3\\\\M_2=0.011mol/dm^3$

The concentration in $g/dm^3$ is $0.011mol/dm^3\times 74g/mol=0.814g/dm^3$

Thus concentration of $Ca(OH)_2$ is $0.011mol/dm^3$ and $0.814g/dm^3$

4 0

3 years ago

In the article "A Sea of Garbage" what message is each cartoon trying to convey to readers? Do they succeed?

sertanlavr [38]

Answer:

yes in the article I see of garbage what's messages each carton trying to convey to your readers with a success obviously they do suck said they succeed because like that's really great day socks said is your garbage is like a pool of garbage work garbage are gathered together they are together a you get one talking about you know when cabbage and together they make efficient use of them okay I mean garbage garbage garbage garbage so I don't know I don't know I don't know I don't know I don't know but it's really is regret it regret it was someone couldn't wish for our young people pick them up and see if garbage and it's really not making sense cuz when you see a sea of garbage that means there's water in there and people pull up garbage in be like water pollution or something but I'm actually not really like sure but I have a slight idea of like what we talking about here right now and it's great

8 0

3 years ago

Question 1:

Alona [7]

Question 1:

(a) Sulfurous acid: H2SO3

Sulfuric acid: H2SO4

(b) Nitrous acid: H2NO2

Nitric acid: H2NO3

Question 2:

To calculate the pH, based on concentration of H+ ions, there is one formula:

$ph = - log_{10}(c(h + ))$

So the pH of this solution is

$- log_{10}( {10}^{ - 9} ) = 9$

(the solution is basic).

5 0

3 years ago

Proton-alpha: "One time I lived in an environment where next door lived identical twins, Proton-beta-1 and Proton-beta-2. Boy, d

Mashcka [7]

Answer:

Explanation:

C) What is the multiplicity of Proton-alpha's signal in this scenario when there are 2 identical protons "next door"?

Based on n+1 rule. Here n=2 (identical beta protons).

2+1=3

So the multiplicity of alpha proton is triplet, .

D) For molecules containing only single bonds (we'll discuss the influence of double bonds in a future lecture), what is the adjective that describes the position of protons that split a "next door neighbor's" signal?

The meaning of the adjective is this: the multiplicity of beta protons is singlet only (no spliting) in absence of alpha proton . But beta protons splits as doublet (n=1) in the presence of alpha proton,

E) How many bonds connect these "splitting next door neighbors"?

There are 3 bonds in between alpha and beta protons in a molecule.

F) What is the multiplicity of the Proton-betas' signal?

Following the n+1 rule, here n=1 (1 alpha proton) so 1+1=2. Hence it is a doublet.

7 0

3 years ago

A scuba diver with a local Sheriff’s office has been assigned the task of retrieving a sunken vessel in the Ocean. The vessel is

n200080 [17]

First, we convert the depth of the water into meters. This is:
60 feet = 18.3 meters

Now, we compute the additional pressure exerted due to the water, which is given by:
Pressure = density * gravitational field strength * height
P = 1000 * 9.81 * 18.3
P = 179.5 kPa

The atmosphere pressure is 101.325 kPa
The pressure of the gas bubbles 60 feet under water will be:
179.5 + 101.325 = 280.825 kPa

The pressure at the surface of the water will be equal to the atmospheric pressure, 101.325 kPa.

Because of this decrease in external pressure as gas bubbles rise, they are seen to expand.

4 0

3 years ago