A student is eating a meat and cheese taco for lunch. After taking a bite he chews his taco into smaller pieces. Then enzymes in the saliva start to break down the carbohydrates in the tacos into simple sugars. Which part of the digestive process best describes a chemical change from the passage above?

Chewing the taco into smaller pieces.

Enzymes in the saliva breaking down carbohydrates into simple sugars

The tongue pushing the taco down his throat.

Swallowing his food down the esophagus

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.