<span>A) elements and compounds.
Compounds are two combined elements.</span>
Explanation:
4. limestone heat lime + carbon dioxide
The reactants in this expression above is limestone
The products of the reaction is carbon dioxide and lime
Reactant is the species that gives the product and it is usually found on the left hand side of the expression.
The product is the substance on the right hand side of the expression that forms through the experiment.
Heat is used to facilitate the reaction.
5. An exothermic reaction is a reaction in which heat is given off.
An endothermic reaction is a reaction in which heat is absorbed in the process.
An exothermic reaction is always warmer after the reaction whereas an endothermic reaction is colder at the end of the reaction.
6. Sodium salicylate is made from carbon dioxide and sodium phenoxide.
The reactants are:
Carbon dioxide and sodium phenoxide
The product is:
Sodium salicylate
Answer:
When a substance is heated ,the kinetic energy of its molecules also increase.
Explanation:
K.E is directly proportional to T
Since plants turn sunlight into glucose (sugar) that humans and animals eat... the energy we get from our food comes indirectly from the sunlight.
Using ideal gas equation,
P\times V=n\times R\times T
Here,
P denotes pressure
V denotes volume
n denotes number of moles of gas
R denotes gas constant
T denotes temperature
The values at STP will be:
P=1 atm
T=273 K
R=0.0821 atm L mol ⁻¹
Mass of HCl given= 49.8 g
Molar mass of HCl given=36.41
Number of moles of gas, n= \frac{Given mass of the substance}{Molar mass of the substance}
Number of moles of gas, n= \frac{49.8}{36.46}
Number of moles of gas, n= 1.36
Putting all the values in the above equation,
V=\frac{1.36\times 0.0821\times 273}{1}
V=30.6 L
So the volume will be 30.6 L.
