Answer:
The melting point range of a substance is the temperature range from which the first crystal starts to melt, to the temperature at which the last crystal finishes melting. An impure substance is a type of mixture, so melting points can be used to find out if a substance is pure or impure.
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Explanation:
Answer:
Na
Explanation:
sodium has mass number 23 and atomic number 11 so number of protons =number of electrons =atomic number which is 11 and number of neutrons=mass number-number of protons =23-11=12
Answer:
18.7887 g of NaCl
Explanation:
<em>The question reads - How many grams of NaCl will be produced from 18.0 g of Na and 23.0 g of Cl2?</em>
Let us start by writing out the balanced equation of the reaction:
Na + Cl2 ---> NaCl2
1 mole, each of Na and Cl2 is required to produce 1 mole of NaCl.
mole = mass/molar mass
Therefore
18 g of Na = 18/23 = 0.7826 mole
23 g of Cl2 = 23/71 = 0.3239 mole
In this case, the Na is in excess and the Cl2 becomes the limiting reagent. Hence
0.3239 mole of Cl2 will react with 0.3239 mole of Na to yield 0.3239 mole of NaCl.
mass of 0.3239 mole NaCl = 0.3239 x 58 = 18.7887 g
<u>Hence, 18.7887 grams of NaCl will be produced from 18.0 g of Na and 23.0 g of Cl2.</u>
Astronomers use the Doppler effect<span> to measure the frequency of light waves as an object is moving with respect to the observer</span>
