Enthalpy is expressed as Delta H, which is the amount of heat content used or released in a system at constant pressure. Delta H equals change in volume multiplied by the constant pressure of the system plus the change in internal energy.
At constant pressure, the heat flow for the process is also equal to the change in enthalpy. Heat flow is expressed as "q." The relationship between Delta H and q can be determined based on whether the reaction is exothermic or endothermic. If the reaction absorbs heat from the surroundings, it is endothermic, and q is positive. If q is positive, then Delta H is also positive. If the reaction releases heat to its surroundings, it is exothermic, and q is negative. If q is negative, then Delta H is also negative.Learn More
The patent for the process to make what people now know as gasoline was filed in 1913. The forerunner of gasoline was around in the 1800s before the invention of the internal combustion engine, but it was only known as a useless by-product of the process used to make kerosene for oil lamps.Full Answer >
The element that has the largest atomic radius is cesium. It has an atomic radius of 298 pm, or picometers. An alkali metal, cesium is so active that it instantly explodes if dropped into cold water. It's also one of the few metals that becomes a liquid at close to room temperature. Its melting point is 83.19 degrees Fahrenheit.Full Answer >
An element is a description of a type of atom, so a single atom is representative of an element but not an element itself. "An atom" refers to a physical entity; "an element" refers to a type of atom.Full Answer >
The mass of NaCl present in a 1 molar solution of NaCl in water depends on the volume of the solution. For example, 1 liter of solution contains 58.44 grams NaCl. The mass of the solute is directly proportional to the volume of solution.Full Answer >