Answer:
1) evolution of gas
2) evolution of heat
Explanation:
In this reaction, glucose is broken down into its constituents; carbon dioxide and water. The question is to decipher indicators of a chemical reaction from the equation.
If we look at the equation carefully, we will notice that a gas was evolved (CO2). The evolution of a gas indicates that a chemical reaction must have taken place. Secondly, energy is given off as heat. This is another indication that a chemical reaction has taken place.
Answer: The correct answer is option B i.e., 2.78 mol
Explanation:
Aluminium reacts with iodine to form Aluminium iodide

From the equation, it is clear that 3 moles of iodine reacts with 2 moles of Aluminium to form Aluminium iodide
We know
For 2 moles of Aluminium, 
3 moles of Iodine reacts with 54 g of Aluminium
? moles of iodine react with 50 g of Aluminium
Answer:
Given, 0.29 g of hydrocarbon produces 448ml of CO2 at STP. then, C2H5 is the emperical formula of hydrocarbon . n = 2 , hence, molecular formula will be C4H10
Answer:
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
Explanation:
This means that a system always has the same amount of energy, unless it's added from the outside.