Percentage of Carbon:
The mass of carbon in 0.2 g of CO$_2$ can be calculated using the molar masses: Molar mass of CO$_2$ = 44 g/mol Molar mass of C = 12 g/mol
Mass of C in 0.2 g CO$_2 = \frac{12}{44} \times 0.2 g = 0.0545g$
Percentage of C $= \frac{Mass of C}{Mass of compound} \times 100 = \frac{0.0545}{0.3} \times 100 = 18.18%$
Percentage of Hydrogen:
The mass of hydrogen in 0.1 g of H$_2$O can be calculated using the molar masses: Molar mass of H$_2$O = 18 g/mol Molar mass of H = 1 g/mol (but there are 2 H atoms, thus, 2 g/mol)
Mass of H in 0.1 g H$_2$O $= \frac{2}{18} \times 0.1g = 0.0111g$
Percentage of H $= \frac{\text{Mass of H}}{\text{Mass of compound}} \times 100 = \frac{0.0111}{0.3} \times 100 = 3.70%$
Therefore, the percentage composition of carbon and hydrogen is 18.18% and 3.70%, respectively.
List I (Spectral Lines of Hydrogen for transitions from) | List II (Wavelength (nm)) | ||
A. | n2 = 3 to n1 = 2 | I. | 410.2 |
B. | n2 = 4 to n1 = 2 | II. | 434.1 |
C. | n2 = 5 to n1 = 2 | III. | 656.3 |
D. | n2 = 6 to n1 = 2 | IV. | 486.1 |
The following diagram shown restriction sites in E. coli cloning vector pBR322. Find the role of ‘X’ and ‘Y’gens :