Final answer:
The weight of a sample of C,H,20. containing 1.7 x 10^23 hydrogen atoms cannot be determined without the correct chemical formula and the molar mass of the compound being specified. So according to me option c is correct.
Step-by-step explanation:
The question 'How much does a sample of C,H,20. weigh if it contains 1.7 x 1023 hydrogen atoms?' involves understanding atomic mass and the mole concept in chemistry. To answer this, we need to first identify the molar mass of hydrogen and then calculate how many moles of hydrogen 1.7 x 1023 atoms represent. However, there seems to be a typo in the chemical formula provided as 'C,H,20.', which makes it challenging to directly compute the weight of the sample without the correct chemical formula or the molar mass of the compound specified.
Nonetheless, if the chemical formula meant 'CH2O' for formaldehyde, which has a molar mass of approximately 30 g/mol, one mole of 'CH2O' contains 6.02 x 1023 hydrogen atoms, following Avogadro's number. This equates to 2 moles of hydrogen atoms because the compound has two hydrogen atoms per molecule. The number of moles represented by 1.7 x 1023 atoms can be calculated and from that, one could derive the mass of the given sample. However, without proper clarification of the formula or the molar mass of the compound, selecting one of the given answer choices would not be feasible.