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3 years ago

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An unknown element, x, reacts with rubidium to form the compound rb2x. in other compounds this element also can accommodate up t

o 12 electrons rather than the usual octet. what element could x be?

1 answer:

SVETLANKA909090 [29]3 years ago

6 0

There are few elements that can form 12 electron rather than the usual 8. Therefore these are the possible answers:

Sulfur = 2Na + S --> Na2S <span>
Selenium = 2Na + Se --> Na2Se
<span>Tellurium = 2Na + Te --> Na2Te</span></span>

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You placed 43.1 g of an unknown metal at 100 °C into a coffee cup calorimeter that contained 50.0 g of water that was initially

nika2105 [10]

Answer :

(a) The heat released by the metal is -312.48 J

(b) The specific heat of the metal is $0.0944J/g^oC$

Explanation :

<u>For part A :</u>

Heat released by the metal = Heat absorbed by the calorimeter + Heat absorbed by the water

$q=[q_1+q_2]$

$q=[c_1\times \Delta T+m_2\times c_2\times \Delta T]$

where,

q = heat released by the metal

$q_1$ = heat absorbed by the calorimeter

$q_2$ = heat absorbed by the water

$c_1$ = specific heat of calorimeter = $51.5J/^oC$

$c_2$ = specific heat of water = $4.184J/g^oC$

$m_2$ = mass of water = 50.0 g

$\Delta T$ = change in temperature = $(T_{final}-T_{initial})=23.2-22.0=1.2^oC$

Now put all the given values in the above formula, we get:

$q=[(51.5J/^oC\times 1.2^oC)+(50.0g\times 4.184J/g^oC\times 1.2^oC)]$

$q=312.48J$

Thus, the heat released by the metal is -312.48 J

<u>For part B :</u>

$q=m\times c\times \Delta T$

q = heat released by the metal = -312.48 J

m = mass of metal = 43.1 g

c = specific heat of metal = ?

$\Delta T$ = change in temperature = $(T_{final}-T_{initial})=23.2-100=76.8^oC$

Now put all the given values in the above formula, we get:

$-312.48J=43.1g\times c\times 76.8^oC$

$c=0.0944J/g^oC$

Thus, the specific heat of the metal is $0.0944J/g^oC$

8 0

3 years ago

Sound waves are mechanical waves in which the particles in the medium vibrate in a direction parallel to the direction of energy

Andre45 [30]

<span>longitudinal waves is the answer hope this helps</span>

5 0

3 years ago

Read 2 more answers

Which metal used in hot water systems

Mrrafil [7]

Answer: Nichrome

Explanation: Hot water system coils are commonly made up of metal alloys which are a combination of two or more elements. The most commonly used metal alloy is “Nichrome”. Nichrome is an alloy of nickel (80%) and chromium (20%).

6 0

3 years ago

Read 2 more answers

16. Explain why antifreeze is used in vehicle radiators. Use your knowledge of the properties of

Fynjy0 [20]

Answer:

Antifreeze is whats used to keep your engine cool without freezing.

Explanation:

it keeps the engine from overheating.

It also prevents corrosion.

Here is a quote from google "Antifreeze works because the freezing and boiling points of liquids are “colligative” properties. This means they depend on the concentrations of “solutes,” or dissolved substances, in the solution. A pure solution freezes because the lower temperatures cause the molecules to slow down"

That quote is from "The Science Behind Antifreeze"

If you have any questions feel free to ask in the comments.

4 0

3 years ago

The tiara worn by Kate Middleton for her wedding to Prince William of England contains 888 diamonds and belongs to the British m

allsm [11]

Answer:

The number of atoms in the gemstones of that tiara is $8.9125\times 10^{24} atoms$ .

Explanation:

Number of diamonds ion tiara = 888

Mass of each diamond = 1.0 carat = 0.200 g (given)

Mass of 888 diamonds in tiara:

$888\times 0.200 g=177.600 g$

Given that diamond is a form of carbon.

Atomic mass of carbon atom = 12 g/mol

Moles of 77.600 g of carbon = $\frac{177.600 g}{12 g/mol}=14.800 mol$

Number of atoms of carbon 14.800 moles:

$14.800 mol\times 6.022\times 10^{23} atoms =8.9125\times 10^{24} atoms$

The number of atoms in the gemstones of that tiara is $8.9125\times 10^{24} atoms$ .

5 0

3 years ago