Answer: Option (B) is the correct answer.
Explanation:
- An ionic bond is formed by the sharing of electrons between two chemically combining atoms.
In an ionic bond, there occurs attraction between oppositely charged ions due to which there occurs strong forces of attraction between them. Therefore, ionic bonds are the strongest bonds.
- A polar covalent bond is formed due to unequal sharing of electrons between the combining atoms.
For example,
is a polar covalent compound. Partial opposite charges tend to develop on the atoms of a polar covalent compound.
- A non-polar covalent bond is formed due to equal sharing of electrons between the combining atoms.
For example,
is a non-polar covalent molecule. No partial charges will be there on the atoms of a non-polar covalent molecule.
- A hydrogen bond is defined as the bond formed between a hydrogen atom and an electronegative atom.
For example, in HCl compound there occurs hydrogen bonding.
In this type of bond, dipole-dipole attractive interactions tend to take place. And, strength of hydrogen bonds is very weak.
Thus, we can conclude that given bond types are arranged in order of increasing strength as follows.
Hydrogen bonds < non-polar covalent bonds < polar covalent bonds < ionic bonds
To find the net ionic equation we must first write the balanced equation for the reaction. We must bear in mind that the reagents Ca(NO3)2 and Na2S are in the aqueous state and as product we will have CaS in the solid state, since it is not soluble in water and NaNO3 in the aqueous state.
The balanced equation of the reaction will be:

Ca(NO3)2(aq) + → Ca(aq) + 2Na(s)NO3Now, c(aq)ompounds in the aqueous state can be written in their ionic form, so the reaction will transform into:Na2S +

So, the answer will be option A
Rates can be calculated with Arrhenius equation k = Axe^(-Ea/RT)
a. temperature affects the rate - imagine you are making coffee, so coffee crystals are boiled faster on higher temperature. Simplified but makes sense.
b. Ea is activation energy. Imagine, while preparing coffee, some of ingredients change to a different one, so there is a A -> B reaction (simplified). Now, Ea is energy barrier that stands on the arrow of this reaction, preventing A to transform to B. If Ea is small, reaction will go easy (not fast!), if Ea is large –reaction will not happen so easy (you ll have to use catalyst for example)
Answer:
5.5 moles of given substance.
Explanation:
The given problem can be solved by using the Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
Solution:
3.311 ×10²⁵ / 6.022 × 10²³ = moles
5.5 moles of given substance.