Answer:
Explanation:
see answer below in the attached file.
<span>A melting point is the characteristic physical property of a substance. So melting point analysis is one of the simplest and most useful techniques for identifing of a chemical substance. Melting point analysis can also provide information about the purity of a sample. A substance containing soluble impurities usually melts at a lower temperature than the pure compound. It can also melt over a wide range of temperatures. The smaller the range of melting temperatures, the higher the purity of the sample.</span>
Answer: -
280mg
Explanation: -
The chemical formula is C14H18N2O5
Molar mass of the compound = 12 x 14 + 1 x 18 + 14 x 2 + 16 x 5 = 294 gram
Number of nitrogen atoms present in the formula = 2
Mass of nitrogen present= 14 x 2 = 28 gram
Thus 294 gram of the compound has 28 gram.
Hence 2.95grams of the compound has (28 gram x 2.95 gram / 294 gram)
= 0.28 gram
= 280 mg
Thus 280 mg of nitrogen is present in 2.95 grams of C14H18N2O5
Answer:
<u>retrograde motion </u>
Explanation:
All the planets have direct motion or progade motion i.e. they move in eastward direction around the Sun. The exceptions are Venus and Uranus which apparently move westwards. This is type of motion is known as retrograde motion. Venus and Uranus move opposite to the other planets motion against the background of stars.
The volume occupied by one mole of any gas at standard temperature(0o) and pressure(1 atm) is 22.4 litres. This volume is a close approximation and different gases vary slightly. The molar volume of any gas at S.T.P. is 22.4L .The mole of any gas can therefore be found using the expression on the right.