What mass of concentrated sulphuric acid 98% by mass must be used to react with completely with 100.0g of calcium phosphate

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

Imagine one batch of soup (batch “a”) is made with 8.19 g/can of salt, according to the recipe, and a second batch of soup (batch “b”) is made with 8.32 g/can of salt. explain which batch would be more resistant to frost damage if it is shipped a great distance in winter and explain why.

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?