How are the lungs kept free of germs and dirt from the air?

How many molecules of ethanol (c2h5oh) (the alcohol in alcoholic beverages) are present in 155 ml of ethanol? the density of ethanol is 0.789 g/cm3?

Two moles of magnesium (Mg) and five moles of oxygen (O2) are placed in a reaction vessel. When magnesium is ignited, it reacts with oxygen. What is the limiting reactant in this experiment? Mg + O2 → MgO (unbalanced) a. Mg b. O2 c. MgO d.

Which substance can be broken down by a chemical change? antimony, carbon, water or sulfur

The heat of reaction for the combustion of c2h4 is - 1411 kj/mol. how many grams of c2h4 must burn

How much heat is released when 30 g of water at 96°C cools to 25°C?

As transformações estão presente em nosso cotidiano, elas nunca param de acontecer, na sua maioria invisível a olho nu. Quais critérios é preciso observar para identificar se ocorreu transformação?

U human ear is measured in?

Is the earth older than any of the rock layers.

Problem page liquid hexane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. what is the theoretical yield of water formed from the reaction of of hexane and of oxygen gas?

Calculate the mass percent of a NaCl solution in which 140g of NaCl is dissolved in 4.50L of water at 25C (density = 0.997g/mL).