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zvonat [6]
3 years ago
7

3. Science has helped people in several ways. The development of medicine to cure disease, pesticides

Chemistry
1 answer:
USPshnik [31]3 years ago
3 0

Answer:

pesticides is the first one

im sorry i cant give you the second  one though

Explanation:

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Which of the following is not present in an atom?<br> Electron<br> Element<br> Neutron<br> Proton
Licemer1 [7]

Answer:

an element is not in an atom

Explanation:

because the only things in a atom are electrons neutrons and protons

4 0
2 years ago
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what is the percent yield of NaCl if 31.0 g of CuCl reacts with excess NaNo3 to produce 21.2 g of NaCl
olchik [2.2K]
Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100  

The Actual Yield is given in the question as 21.2 g of NaCl.  However, in order to find the theoretical yield, you have to write a balanced equation and use the mole ratio to calculate the mass of NaCl that would be produced.

Balanced Equation:   CuCl + NaNO₃    →    NaCl + CuNO₃

Moles of CuCl = Mass of CuCl ÷ Molar Mass of CuCl
                         =  31.0 g ÷ (63.5 + 35.5)g/mol
                         = 0.31 mol

the mole ratio of CuCl to NaCl is 1  :  1,
∴ if moles of CuCl = 0.31  mol,

then moles of NaCl = 0.31 mol

Now, Mass of NaCl = Moles of NaCl × Molar Mass of NaCl
                                 =  0.31 mol × (23 + 35.5) g/mol
                                 =  18.32 g

⇒ the THEORETICAL Yield of NaCl, in this case, is 18.32 g.

Now, since Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100  

⇒ Percentage Yield of NaCl = (21.2g ÷ 18.32g) × 100  
                                                = 115.7 %


NOTE: Typically, the percentage yield of a reaction is less than 100%, however in a case where the mass of the substance is weighed with impurities, then that mass may be in excess of 100% as seen here.
4 0
3 years ago
What is an acid and also what is a base​
expeople1 [14]

Answer:

An acid is a substance that donates protons (in the Brønsted-Lowry definition) or accepts a pair of valence electrons to form a bond (in the Lewis definition). A base is a substance that can accept protons or donate a pair of valence electrons to form a bond.

Hope it helps!!!

3 0
2 years ago
How does an electromagnet create a magnetic field
777dan777 [17]
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire create a magnetic field which is concentrated in the hole, denoting the center of the coil
8 0
2 years ago
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What is the molar mass of NaC2H302?
andrezito [222]

Answer:

82.0343 g/mol

Explanation:

Count each element and the number of atoms for each element. Add them all together. Use the periodic table.

3 0
2 years ago
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