Question

1. Classify each of the following as a pure substance or a mixture,if it is a mixture, state whether it is heterogeneous or homogeneous: (a)concrete,(b) tomato juice,(c)marble,(d)seawater, and (e)iron?

2.what distinguishes a mixture from an impure subastance?

3.Define the process of sublimation?

5.How do decantation and filtration differ?which should be faster?

6. why should you never place a hot object on the pan of a balance?

7. A student found that her mixture was 13% NH4CL, 18%NACL, and 75% sio2. Assuming that her calculations are correct, what did she most likely do incorrectly in her experiment?

Answer 1

1.Classify each of the following as a pure substance or a mixture,if it is a mixture, state whether it is heterogeneous or homogeneous:

(a)concrete = a mixture, heterogeneous

(b) tomato juice = a mixture, heterogeneous

(c) marble = a mixture, heterogeneous

(d) seawater = a mixture, homogenous

(e)iron = pure substance,homogenous

2. An impure substance is one substance contaminated with small amounts of one or more other substances. A mixture is two or more pure substances.

3. The process of changing from a solid to a gas without passing through an intermediate liquid phase.

6.Because it Will burn through the balance pan