how many moles of silicon are in 245 g of silicon? a. 8.72 mol b. 28.0 mol c. 1.10 10-1 mol d. 6.90 103 mol

1 answer:

7 0

Atomic mass silicon = 28.085 u

1 mol Si ---------------- 28.085 g
? ------------------------ 245 g

245 x 1 / 28.085 => 8.72 mol

answer A

You might be interested in

when a reactive metal is added to water, bubbles or fizzing can be observed. Explain the appearance of the bubbles

MakcuM [25]

Answer:

This is because of the release of hydrogen gas in the reaction.

Explanation:

Metals react with water and produce a metal oxide and hydrogen gas. It also starts floating due to the bubbles of hydrogen gas sticking to its surface.

For eg:

2Mg. + 2H2O --------> 2MgOH + H2

Here,

Metal taken is magnesium(2Mg) which when reacts with water(2H2O) to form its oxide form (2MgOH) and hydrogen gas(H2) is released which comes outside water as bubbles.

7 0

3 years ago

Please help with Chemistry! Very urgent! I’ll give you 40 points

kvv77 [185]

Answer: 3. No displacement, zinc is most reactive.

4. Calcium Chloride, Calcium is most reactive.

5. No displacement, Copper is most reactive

6. No displacement, Calcium is most reactive

7. Hydrogen Oxide, Hydrogen is most reactive

8. Carbon oxide, Carbon is most reactive

9. No displacement, Aluminum is most reactive

10. Potassium Kryptide + Lead, no displacement, Potassium is most reactive.

5 0

3 years ago

The surface temperatures on land vary more over the course of a year than the surface temperatures on the ocean because land has

bogdanovich [222]

Answer:

Lower heat capacity

Explanation:

The heat or thermal capacity is a physical property defined as the amount of heat a material need in order to elevate a unit in its temperature, this means that water increases its temperature more easily than land.

I hope you find this information useful and interesting! Good luck!

7 0

3 years ago

What are the rows of the periodic table called?

Arlecino [84]

Answer:

i believe its called A. periods

4 0

2 years ago

What else supports the idea that an exothermic reaction has occurred?

kodGreya [7K]

The main pieces of evidence that an exothermic reaction has occurred is an increase in temperature due to the release of energy, a release of energy in the form of light, or a release of gas.

4 0

3 years ago