Answer:
1. Both are made up of two substances that are chemically combined. 2. oxygen(O2) , 3. CARBON (C) , 4. AIR(N2 nixed with O2 AND CO2), 5. CANNOT BE SEPARATED BY PHYSICAL MEANS
Explanation:
<em>HOPE IT HELPS</em>
Answer:
Explanation:
Physical change is a temporary and reversible change in which the physical properties of the substance changes without altering the composition of the substance Eg Melting of ice while chemical change is a permanent and not so easily reversible change in which the identity of the substance is altered to produce one or more substances Eg Combustion
Answer:
The concentration the student should write down in her lab is 2.2 mol/L
Explanation:
Atomic mass of the elements are:
Na: 22.989 u
S: 32.065 u
O: 15.999 u
Molar mass of sodium thiosulfate, Na2S2O3 = (2*22.989 + 2*32.065 + 3*15.999) g/mol = 158.105 g/mol.
Mass of Na2S2O3 taken = (19.440 - 2.2) g = 17.240 g.
For mole(s) of Na2S2O3 = (mass taken)/(molar mass)
= (17.240 g)/(158.105 g/mol) = 0.1090 mole.
Volume of the solution = 50.29 mL = (50.29 mL)*(1 L)/(1000 mL)
= 0.05029 L.
To find the molar concentration of the sodium thiosulfate solution prepared we use the formula:
= (moles of sodium thiosulfate)/(volume of solution in L)
= (0.1090 mole)/(0.05029 L)
= 2.1674 mol/L
Answer:
Q3. A bridge is built without expansion gaps.
Explain what could happen to the bridge if the temperature became:
a) much hotter than the day it was built.
b) much colder than the day it was built.
P.s. (this is not a select option question, explain each according to the question)
On the cumulative Report, it would be much easier to read for the patients if the ranges in parentheses were tabbed over from the actual result instead of printing directly one space after the result.
