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3 years ago

Chose all the right answers

Chemistry

2 answers:

lozanna [386]3 years ago

4 0

Burning paper hope this helped

Rashid [163]3 years ago

3 0

Answer:

Iron Rusting

Burning Paper

Digesting your lunch

Explanation:

These can't be turned back into their past forms is one way to identify if it's a chemical change.

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Gallium is produced by the electrolysis of a solution made by dissolving gallium oxide in concentrated NaOH ( aq ) . Calculate t

Sedbober [7]

Answer:

Approximately $6.30\times 10^{-3}\;\rm mol$ .

Explanation:

The gallium here is likely to be produced from a $\rm NaGaO_2\, (aq)$ solution using electrolysis. However, the problem did not provide a chemical equation for that process. How many electrons will it take to produce one mole of gallium?

Note the Roman Numeral " $\mathtt{(III)}$ " next to $\rm Ga$ . This numeral indicates that the oxidation state of the gallium in this solution is equal to $+3$ . In other words, each gallium atom is three electrons short from being neutral. It would take three electrons to reduce one of these atoms to its neutral, metallic state in the form of $\rm Ga\, (s)$ .

As a result, it would take three moles of electrons to deposit one mole of gallium atoms from this gallium $\mathtt{(III)}$ solution.

How many electrons are supplied? Start by finding the charge on all the electrons in the unit coulomb. Make sure all values are in their standard units.

$t = \rm 80.0\; min = 80.0\; min \times 60\;s \cdot min^{-1} = 4800\; s$ .

$Q = I \cdot t = \rm 0.380 \; A \times 4800 \; s = 1.824\times 10^3\; C$ .

Calculate the number of electrons in moles using the Faraday's constant. This constant gives the size of the charge (in coulombs) on each mole of electrons.

$\begin{aligned} n(\text{electrons}) &= \frac{Q}{F} \cr &= \rm \dfrac{1.824\times 10^3\; C}{96485.332\; C \cdot mol^{-1}}\cr &\approx \rm 1.89\times 10^{-2}\; mol \end{aligned}$ .

It takes three moles of electrons to deposit one mole of gallium atoms $\rm Ga\, (s)$ . As a result, $\rm 1.89\times 10^{-2}\; mol$ of electrons would deposit $\displaystyle \rm \frac{1}{3}\times 1.89\times 10^{-2}\; mol \approx 6.30\times 10^{-3}\; mol$ of gallium atoms $\rm Ga\, (s)$ .

8 0

3 years ago

The Difference Between an Alloy and an Amalgam

Delicious77 [7]

Mixtures or combinations of various different metals or metallic substances form things called alloys. An alloy composed of mercury and other metal (or metals) forms "amalgam". When a true alloy is created, the component metals are combined together at a temperature which is greater than the melting point of all of them.

Also, it helps to remember the word "amalgamate", which means "to alloy (a metal) with mercury" according to Dictionary.com.

Hope this helped :)

(btw I'm like 3 brainliest answers away from my next rank so could you...you know... :)

6 0

4 years ago

2. Fluorine gas exerts a pressure of 1.2 atm. When the

Mariana [72]

Answer:

look at the photo........................

6 0

2 years ago

An instrument that is used to measure air pressure is a ?

Zolol [24]

A barometer measures atmospheric pressure.

8 0

3 years ago

I have attached all the problems, but really if you just do one so I understand how to do it, that would be great!

Ivahew [28]

Answer:

Answer of question a is 345J.

Explanation:

In question a following is given in data:

-mass of iron (m) = 10.0 g

-temperature (ΔT) = final temperature- initial temperature= 100-25= 75 degree Celsius

-Specific Heat capacity of iron (c)= 0.46J/g°C.

Heat (Q)=?

Solution:

Formula for Heat is :

Q=m x c x ΔT

Q= 10 x 0.46 x 75

Q= 345 J.

so, 345 joules of heat is needed to increase the temperature of 10 grams of iron.

From the above formula all other questions can easily be solved from the same procedure.

4 0

4 years ago