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Amiraneli [1.4K]
3 years ago
5

Name the hardest artificial substance known?

Chemistry
2 answers:
3241004551 [841]3 years ago
6 0

Answer:

wurtzite boron nitride

Scientists have calculated that wurtzite boron nitride has a greater indentation strengths than diamond.

blagie [28]3 years ago
4 0
The hardest material is diamond. The hardest artificial substance would wurtzite boron nitride. That's basically just man-made diamonds.
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5.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 7
slega [8]

Answer:

The molecular formula = C6H6

Explanation:

Step 1: Data given

Mass of compound X = 5.00 grams

Mass of products =

  CO2 = 16.39 grams

  H2O = 3.46 grams

Molar mass CO2 = 44.01 g/mol

Molar mass H2O = 18.02 g/mol

Molar mass C = 12.01 g/mol

Molar mass H = 1.01 g/mol

Molar mass O = 16. 0g/mol

Step 2: Calculate moles

Moles = mass / molar mass

Moles CO2 = 16.93 grams / 44.01 g/mol

Moles CO2 =  0.385 moles

Moles C = 1* 0.385 = 0.385 moles

Moles H2O = 3.46 grams / 18.02

Moles H2O = 0.192 moles

Moles H = 2* 0.192 = 0.384 moles

Step 3: Calculate mass

Mass = moles * molar mass

Mass C = 0.385 moles *12.0 g/mol

Mass C = 4.62 grams

Mass H = 0.39 grams

Mass O = 5.00 - 4.62 -0.38 moles

Mass O = 0 grams

Step 4: Calculate mol ratio

We divide by the smallest amount of moles

C: 0.385 moles / 0.384 = 1

H: 0.384 moles / 0.384 = 1

The empirical formula is CH

This molecular formula is 13 g/mol

We have to multiply the empirical formula by n

n = 78 g/mol / 13 g/mol

n = 6

The molecular formula = 6*(CH) = C6H6

4 0
3 years ago
A particular laser consumes 130.0 Watts of electrical power and produces a stream of 2.67×1019 1017 nm photons per second.
solniwko [45]

The missing question is:

<em>What is the percent efficiency of the laser in converting electrical power to light?</em>

The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.

A particular laser consumes 130.0 Watt (P) of electrical power. The energy input (Ei) in 1 second (t) is:

Ei = P \times t = 130.0 J/s \times 1 s = 130.0 J

The laser produced photons with a wavelength (λ) of 1017 nm. We can calculate the energy (E) of each photon using the Planck-Einstein's relation.

E = \frac{h \times c }{\lambda }

where,

  • h: Planck's constant
  • c: speed of light

E = \frac{h \times c }{\lambda } = \frac{6.63 \times 10^{-34}J.s  \times 3.00 \times 10^{8} m/s }{1017 \times 10^{-9} m }= 6.52 \times 10^{-20} J

The energy of 1 photon is 6.52 × 10⁻²⁰ J. The energy of 2.67 × 10¹⁹ photons (Energy output = Eo) is:

\frac{6.52 \times 10^{-20} J}{photon} \times 2.67 \times 10^{19} photon = 1.74 J

The percent efficiency of the laser is the ratio of the energy output to the energy input, times 100.

Ef = \frac{Eo}{Ei} \times 100\% = \frac{1.74J}{130.0J} \times 100\% = 1.34\%

The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.

You can learn more about lasers here: brainly.com/question/4869798

8 0
3 years ago
Calculate the empirical formula of a compound that has a composition of 5.9% (by mass) hydrogen and 94.1% (by mass) oxygen.​
adelina 88 [10]

Answer:

The empirical formula is the simplest form;

Given:

Oxygen O at 94.1% and

H at 5.9%

Assume 100grams.

94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O

5.9% = 0.059 x 100gm. = 5.9gm. X 1moleH/1.002gm. = 5.88 moles of H

There is one mole of O for each mole of H so the empirical formula is O_1H_1

and written as OH.

8 0
3 years ago
Read 2 more answers
Chemical formula for Potassium Hydrogen Nitrate
My name is Ann [436]

Answer:

KNO3

Explanation:

8 0
3 years ago
Question 12 A chemistry student must write down in her lab notebook the concentration of a solution of sodium thiosulfate. The c
o-na [289]

Weight of sodium thiosulfate   = 76.148 - 8.2

= 67.948 g.

Concentration of the solution = 67.948 / 172.7

= 0.393 g / mL.  to the nearest thousandth . (answer).

3 0
3 years ago
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