Answer:
669.48 kJ
Explanation:
According to the question, we are required to determine the heat change involved.
We know that, heat change is given by the formula;
Heat change = Mass × change in temperature × Specific heat
In this case;
Change in temperature = Final temp - initial temp
= 99.7°C - 20°C
= 79.7° C
Mass of water is 2000 g ( 2000 mL × 1 g/mL)
Specific heat of water is 4.2 J/g°C
Therefore;
Heat change = 2000 g × 79.7 °C × 4.2 J/g°C
= 669,480 joules
But, 1 kJ = 1000 J
Therefore, heat change is 669.48 kJ
Answer:
The over all charge on atom will be +2.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
X is the element having 12 protons 10 electrons and 14 neutrons.
The number of protons and electrons are not equal which means two electrons are lose by the given atom and it is present in the form of cation.
The over all charge on atom will be +2.
2KMnO4+3Na2SO3+H2O→2MnO2+3Na2SO4+2KOH
In a reaction, the reducing agent is the element or compound that donates electron or the one tht loses electrons. The oxidized species. The opposite is called the oxidizing agent. It is the one who accepts the electrons lost. For this reaction KMnO4 is reduced into MnO2.
The formula Ca(ClO3)2 breaks down to: 1 calcium atom, 2 chlorine atoms, and 6 oxygen atoms. Therefore:
One molecule of calcium chlorate contains 9 atoms [correct]
Calcium chlorate is not an element, nor does the molecule contain only 3 atoms [incorrect]
It does not take 9 different elements - just the three elements we listed [incorrect]
Calcium chloride only contains one Ca group [incorrect]
