Is “ the silver spoons tarnished and turned black” physical or chemical property?

How many moles of copper are needed to react with sulfur to produce 0.25 moles Ol

Tems11 [23]

Answer:

0.50 moles of Cu

Explanation:

The balanced chemical equation for given synthetic reaction is,

2 Cu + S → Cu₂S

According to balance chemical equation,

1 mole of Cu₂S is produced by = 2 moles of Cu

So,

0.25 moles of Cu₂S will be produced by = X moles of Cu

Solving for X,

X = 0.25 mol × 2 mol / 1 mol

X = 0.50 moles of Cu

Hence, as the molar ratio of Cu to Cu₂S is 2:1 hence, to produce 0.25 moles of Cu₂S we will need 0.50 moles of Cu.

6 0

3 years ago

Different isotopes of the same element emit light at slightly different wavelengths. A wavelength in the emission spectrum of a

Inessa [10]

Different isotopes of the same element emit light at slightly different wavelengths, the minimum number of slits is mathematically given as

N=1820slits

<h3>What minimum number of slits is required to resolve these two wavelengths in second-order?</h3>

Generally, the equation for the wave is mathematically given as

$d\ sin\ (\theta\ m) \ = \ m\ \lambda$

Where the chromatic resolving power (R) is defined by

$R\ =\ \lambda\ / \ d \ \lambda$

R = nN,

Therefore

$\lambda_1 \ = \ (656.45)(1 \ * \ 10^{-9})/1mm$

$\lambda_1= 656.45*10^{-9}$

and

$\lambda_2= (656.27)(1*10^{-9})/1mm$

$\\\\\lambda_2= 656.27*10^{-9}m$

In conclusion, the minimum number of slits is required to resolve these two wavelengths in second-order

$N\ =\ \dfrac{\lambda}{m\ d\ T\ }\\\\$

Therefore

$N\ =\ \dfrac{656.45 \ * \ 10^{-9}}{2\ * \ (0.18*10^{-9})}$

N=1820slits

Read more about slits

brainly.com/question/24305019

#SPJ1

7 0

1 year ago

White phosphorus is composed of tetrahedral molecules of P4 in which every P atom is connected to three other P atoms. In the Le

Dmitrij [34]

Answer:

In the Lewis structure of P4 there are 6 bonding pairs and 4 lone pairs of electrons.

Explanation:

The structure of tetrahedral molecule of P4 is provided below.

Each phosphorus atom has 5 valence electrons out of which 3 electrons involve in bonding and the rest 2 electrons exist as a lone pair that does not involve in bonding.Hence each phosphorus atom has one lone pair.In P4 molecule there are phosphorus atoms and hence 4 lone pairs in total.

As you can see in the figure, each phosphorus atom is bonded to the other three atoms.A bond is formed when two atoms share one electron each and the pair is called bonding pair.

From the figure we can see that there are 6 bonds in total.Each bond consist of one bonding pair of electrons and hence in total there are 6 bonding pairs of electrons.

Hence in a P4 molecule there are six bonding pairs and 4 lone pairs of electrons.

4 0

3 years ago

Which of the following is a physical change?

Anit [1.1K]

I’m pretty sure cooking an egg could be it

8 0

2 years ago

Predict the reactivity of silicon in water relative to that of sodium, magnesium, and aluminium. Explain your answer. How does t

Inessa [10]

Answer:

See explanation

Explanation:

The reactivity of metals has a lot to do with their position in the electrochemical series. However, it is also known that metallic character decreases across the period. This implies that as we move from left to right along the periodic table. Sodium, magnesium, aluminum and silicon continues to decrease in metallic character. As a matter of fact, silicon is a metalloid and not a pure metal.

Sodium reacts with cold water to give a vigorous reaction,magnesium and aluminium reacts with steam at red heat.

Silicon does not react with water, even as steam, under normal conditions.

5 0

2 years ago