6a. physical reaction
6b. endothermic reaction
7a. physical reaction
7b. the reactants are carbon dioxide, water and light energy. the product is starch
7c. exothermic reaction
Water and hydrogen peroxide are different compounds although they have the same kind of atoms. The molecular formula of water is H2O (two atoms of oxygen chemically bonded to one atom of oxygen). The molecular formula of hydrogen peroxide is H2O2, (each atom of oxygen is chemical bonded to one atom of H and other atom of O). So,<span> the presence of different chemical bonds leads to different products with different chemical properties.</span><span />
When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant
Answer:
m = 50.74 kg
Explanation:
We have,
Initial temperature of water is 20 degrees Celsius
Final temperature of water is 46.6 degrees Celsius
Heat absorbed is 5650 J
It is required to find the mass of the sample. The heat absorbed is given by the formula ad follows :
c is specific heat of water, c = 4.186 J/g°C
So,
So, the mass of the sample is 50.74 kg.
Explanation:
The <u>First Law of Thermodynamics</u> states that energy cannot be created or destroyed in an isolated system. In other words, energy can be converted from one form into another, but it cannot be created nor destroyed.
<u>Conduction</u> is the transfer of energy from one molecule to another by direct contact. This transfer occurs when molecules hit against each other, which can take place in solids, liquids, and gases.
When you put your cold hands under your legs to warm your hands up, the heat energy from your legs is being transferred to your hands through conduction. However, since energy cannot be created, there is no extra heat energy that can instantaneously replace the heat created by your legs.
