Answer:
3grams
Explanation:
The reaction for the production of Magnesium dioxide will be
Mg + O2 → MgO
we have 5g of MgO (molar mass 40g)
no of moles of MgO = 5/40 = 0.125
Using unitary method we have
1 mole of Mg require 1 mole of MgO
0.125 Mole of MgO = 0.125mole of Mg
n = given mass /molar mass
0.125 = mass / molar mass
mass = 0.125* 24 = 3grams
B.) Its particles are packed together tightly.
Answer is: c. impulse acting on the object.
Momentum is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction in three-dimensional space.
The impulse-momentum change equation: F· t = m · Δ v.
The impulse experienced by the object equals the change in momentum of the object.
Answer:
The lanthanides and actinides together are sometimes called the inner transition elements.
Explanation:
They are called this because they come up in the periodic table after actinium
Hope this helps :)
Answer:
1. The change in energy is 60KJ or 6.0 × 10^1 KJ
2. Endothermic reaction
Explanation:
The Enthalpy (ΔU) for the mixture is given as 215kJ and the workdone (W) on the mixture is - 155KJ. Hence, the change in the energy (ΔH) ofthe mixture is computed using the equation below:
ΔH = ΔU + w
Where,
ΔH= Change in energy
ΔU= Enthalpy change
W= workdone
Therefore ΔH is:
ΔH= 215 kJ + (-155Kj)
ΔH= 60 KJ
Therefore, the change in energy is 60KJ or 6.0 × 10^1 KJ
The value is positive so it is an endothermic reaction.
An endothermic reaction happens when the energy used to break the bonds in the reactants is higher than the energy given out when bonds are formed in the products. This means that the entire reaction takes in energy, hence there is a temperature decrease in the surroundings. Endothermic reactions cannot happen spontaneously. Work is usually done in order to get these reactions to occur. When endothermic reactions absorb energy, a temperature drop is measured by the reaction.
