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worty [1.4K]
3 years ago
15

Robots have been around since the 3rd century BC. At that time, they were mainly invented as toys to amuse the king or emperor.

Chemistry
2 answers:
Sergeeva-Olga [200]3 years ago
8 0

Answer:

B. I and II only  

Explanation:

For example, unmanned space probes can gather information more easily than a human can.

Closer to home, many biochemical research and pharmaceutical industries use pipetting robots for their repetitive pipetting chores.

C is wrong.  Machines can do things faster than any human ever could and not get tired, but humans possess the intelligence, expertise, and skills to use the robots most efficiently and to solve problems when things go wrong.

timama [110]3 years ago
6 0
A I think sorry if it’s wrong
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You have 4.72x10^25 atoms of a substance with MW of 136.94 g/mol How many moles do you have
slega [8]

Number of moles = 78.41

<h3>Further explanation  </h3>

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

4.72 x 10²⁵ atoms of a substance, then moles :

\tt n=\dfrac{N}{No}\\\\n=\dfrac{4.72\times 10^{25}}{6.02\times 10^{23}}\\\\n=78.41

4 0
3 years ago
ethylene glycol, commonly used in automobile antifreeze, contains only carbon, hydrogen and oxygen.combustion analysis of a 23.4
Kay [80]

Answer:

Molecular formula of ethylene glycol is C₂H₆O₂.

Explanation:

Given data:

mass of ethylene glycol = 23.4 mg

mass of water = 20.42 mg

mass of carbon dioxide = 33.27 mg

molar mass of ethylene glycol = 62.0 g / mol

Molecular formula of ethylene glycol = ?

Solution:

percentage of carbon = (33.27 mg/ 23.46 mg) × (12 /44) × 100

                                      =  (1.4182× 0.27) × 100 = 38.29

percentage of hydrogen =  (20.42 mg/ 23.46 mg) × (2 /18) × 100

                                          = (0.8704× 0.11) × 100 = 9.67

percentage of oxygen = 100 - (38.29 + 9.67 )

                                      = 100 - 47.96 = 52.04

Now we will determine the number of grams atoms of carbon, hydrogen and oxygen.

No. of gram atoms of carbon = 38.29 /12 = 3.19

No. of gram atoms of hydrogen = 9.67 / 1 = 9.67

No. of gram atoms of oxygen = 52.04 / 16 = 3.25

Atomic ratio:

     C :H :O               3.19/ 3.19    :   9.67 / 3.19   :  3.25 /3.19

     C :H :O                 1 : 3 : 1

Molecular formula:

    Molecular formula = n × (empirical formula)

    n = molar mass of compound / empirical formula mass

    empirical formula mass= 1 × 12 + 3 × 1  + 1 × 16

     empirical formula mass= 12+3 +16 = 31

                  n = 62 g /mol / 31 = 2

         Molecular formula = n × (empirical formula)

         Molecular formula = 2 × (CH₃O)

          Molecular formula = C₂H₆O₂

6 0
3 years ago
How many atoms are in 1.14 mol of sulfur trioxide
yawa3891 [41]
2.75 x 10^24

Hope this helped :)
8 0
3 years ago
A solution is made by mixing equal masses of methanol, CH 4 O , and ethanol, C 2 H 6 O . Determine the mole fraction of each com
Fynjy0 [20]

Answer:

Mole fraction of CH_4O = 0.58

Mole fraction of C_2H_6O = 0.42

Explanation:

Let the mass of CH_4O and C_2H_6O = x g

Molar mass of CH_4O = 33.035 g/mol

The formula for the calculation of moles is shown below:

moles = \frac{Mass\ taken}{Molar\ mass}

Thus,

Moles_{CH_4O}= \frac{x\ g}{33.035\ g/mol}

Moles_{CH_4O}=\frac{x}{33.035}\ mol

Molar mass of C_2H_6O = 46.07 g/mol

Thus,

Moles= \frac{x\ g}{46.07\ g/mol}

Moles_{C_2H_6O}=\frac{x}{46.07}\ mol

So, according to definition of mole fraction:

Mole\ fraction\ of\ CH_4O=\frac {n_{CH_4O}}{n_{CH_4O}+n_{C_2H_6O}}

Mole\ fraction\ of\ CH_4O=\frac{\frac{x}{33.035}}{\frac{x}{33.035}+\frac{x}{46.07}}=0.58

Mole fraction of C_2H_6O = 1 - 0.58 = 0.42

6 0
4 years ago
Nuclear energy is released during:
kondaur [170]
B, C and E. In radioactive decay unstable atoms stabilize by releasing energy.
3 0
3 years ago
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