A sample of oxygen is collected over water at a total pressure of 690.7 mmHg at 19°C. If the vapor pressure of water at 19°C is 16.5 mmHg, then what is the partial pressure of the O2 in the sample in units of atmospheres?

Iknow #2 is d. i just need to know why

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process