Hello!
The number of 20-g ice cubes required to absorb 47 kJ from a glass of water upon melting is 7 icecubes
Why?
We are going to clear from the equation of the released heat, the mass of ice (m). The specific latent heat of fusion of ice is 336 kJ/kg:

So, 7 ice cubes are required to absorb that amount of heat from the glass of water.
Have a nice day!
B A C ( Blood Alcohol Content ) of 0.10 means that there are 0.10 g of alcohol for every dl of blood.
5 L = 50 dl
50 * 0.10 g = 5 g
In his blood is circulating 5 grams of alcohol.
The IUPAC name of NO is nitric oxide. It is one of the many oxides of nitrogen. It is a colorless gas under standard temperature and pressure. It found great application in the combustion of fossil fuels in power plants. This substance is produced naturally by lightning.