試題詳解

複選題
1. Which of the following statements about the nature of analytical chemistry is (are) correct? (AB) Amaterial is homogeneous if its constituent parts can be distinguished only with the aid of a microscope. (AC) The preparation of a solid Iaboratory sample involves grounding the solid to decrease particle size. mixing to ensure homogeneity, and storing for various lengths of time before analysis begins. (AD) Techniques or reactions that work for only one analyte are said to be selective. (AE) An interferent causes an error in an analysis by attenuating (making smaller) the quantity being measured, whereas an interference causes an error by enbancing the quantity. (BC)We compute the results of a typical quantitative analysis from two mea ments. One is the mass or the volume of sample being analyzed. The second mcasurement is of some quantity that is proportional to the amount of analyte in the sample. (BD) In gravimetric methods. we determine the volume of the analyte or some compound chemically related to it.