Answer: The activation energy is 10 kJ and the reaction is exothermic.
Explanation: Exothermic reactions are those in which heat is released and thus the energy of products is less than the energy of reactants.
Endothermic reactions are those in which heat is absorbed and thus the energy of products is more than the energy of reactants.
Activation energy is the extra amount of energy required by the reactants to cross the energy barrier to convert to products.
Given : Energy of reactants = 40kJ
Energy of activation: (50-40)=10 kJ
Energy of products = 50 kJ
Energy of products = 15 kJ
Thus Energy of products (15kJ) < Energy of reactants(40kJ), the reaction is exothermic as energy has been lost to surroundings in the form of heat.
Steel
Fabric (Cotton, Polyester, Felt)
Plastic
Wood
Paper
Answer:

Explanation:
The products of this reaction are given by:

Firstly, dichromate anion becomes chromium(III) cation, let's write this change:

The following steps should be taken:
- balance the main element, chromium: multiply the right side by 2 to get 2 chromium species on both side:

- balance oxygen atoms by adding 7 water molecules on the right:

- balance the hydrogen atoms by adding 14 protons on the left:

- balance the charge (the total net charge on the left is 12+, on the right we have 6+, so 6 electrons are needed on the left):

Similarly, tin(II) cation becomes tin(IV) cation:

Now that we have the two half-equations, multiply the second one by 3, so that it also has 6 electrons that will be cancelled out upon addition of the two half-equations:


Add them together:

Adding the ions spectators:

Answer:

Explanation:
The formula for the heat released is
q = mCΔT
Data:
m = 395 g
C = 4.184 J·°C⁻¹g⁻¹
ΔT = 55 °C
Calculations:
q = 395 × 4.184 × 55 = 91 000 J = 91 kJ
The water will absorb
of energy.
Answer:
The molecules move slower than the temp of 50°c and their average kinetic energy decreases.
Explanation:
kinetic energy cannot increase as temperature is reduced. molecules will still move with reduced motion.