Acube of aluminum is 20 cm on edge. aluminum has a density of 2.7 g/cm3 and a specific heat of 0.217 cal/g0c. what is the heat in calories needed to raise the temperature of the cube from 200 to 3000c?

A common unit of energy is the calorie. A calorie is defined as the amount of heat that is needed to raise the temperature of one gram of water one degree centigrade. Modern convention uses a unit of energy called a joule. A calorie is equal to 4.184 joules. A joule is approximately the energy needed to lift 2000 grams a distance of 10 centimeters.

Heat is transferred by either direct transfer from one object touching another or by the emission of radiation in the form of infrared radiation. Two results can occur as a result of this transfer of thermal energy. A substance can undergo either a change in temperature or a change in physical state.

When a substance exchanges heat with its surroundings without changing its physical state, the substance will undergo a change in temperature. This change in temperature depends on a property called specific heat capacity.

Specific heat capacity is the "heat needed to produce a given temperature change (in Celsius or Kelvin) per gram of substance" and is expressed in the units J/gK. Specific heat capacity depends on both the type of substance and the mass of the substance.The "D" means "change in" and "q" represents the quantity of heat.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

→

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%