Answer:
the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula
Explanation:
Mass of CO2 obtained = 3.14 g
Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol
The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g
Mass of H2O obtained = 1.29 g
Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol
The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g
% by mass of carbon = 0.857/1 ×100 = 85.7 %
% by mass of hydrogen = 0.0717/1 × 100 = 7.17%
Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %
Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.
Gamma rays can transmit through matter.
Answer:
= 17% (v/v)
Explanation:
% by Volume = (Volume HCl / Volume of Solution)100%
= 15ml/(75ml + 15ml) x 100% = 16.66666667% (calculator answer)
= 17% (v/v) 2 sig figs. based on volume values given.
Answer:
The correct option is GRADUATED CYLINDER.
Explanation:
Each of the glassware used in the laboratory has its specific functions. The graduated cylinder is especially manufacture to facilitate the measurement of accurate volume of liquids in the laboratory. Measurements obtained by means of graduated cylinder can be considered to be moderately accurate; volumentric flasks are more accurate than graduated cylinder and should be used when higher precision are required.
Answer:Four types of vaccines are currently available: Live virus vaccines use the weakened (attenuated) form of the virus. The measles, mumps, and rubella (MMR) vaccine and the varicella (chickenpox) vaccine are examples
