Final answer:
The percent composition of potassium in the sample is 52%. So, the appropriate option is (d).
Step-by-step explanation:
To find the percent composition of potassium in the sample, you divide the mass of potassium by the total mass of the compound and then multiply by 100. In this case, the mass of potassium is 4.5 g, and the total mass of the compound is the sum of potassium, nitrogen, and oxygen, which is 8.5 g (4.5 g + 2.8 g + 1.2 g).
Percent composition of potassium = (Mass of potassium / Total mass of sample) * 100
= (4.5 g / 8.5 g) * 100
= 0.5294 * 100
= 52.94%
Therefore, the percent composition of potassium in the sample is approximately 52.94%.
Among the given options, the closest one is (d) 52%, which represents a reasonable approximation. The discrepancy may arise from rounding during calculations or variations in the precision of the given options. Therefore, option (d) 52% is the most appropriate choice given the available options.