Answer:
3. is an endothermic process.
Explanation:
Generally, reactions can be classified into two. Depending on whether they absorb heat -energy or release energy.
Endothermic Reactions are those reactions in which the reaction absorb heat form the surroundings.
Exothermic reactions are those reactions that release heat to the surroundings.
This means the correct option is;
3. is an endothermic process.
Physical. No change in molecules. It goes from hard to liquid.
Answer:
6.67 M
Explanation:
Molarity =
<em>Convert 200g NaOH to moles. Convert 750 mL to L.</em>
200 g NaOH x (1 mol/39.998 g) = 5.00025... mol NaOH
750 mL x (1 L/1000 mL) = 0.750 L
<em>Substitute values into the equation.</em>
Molarity =
Molarity = 6.667... M
Molarity = 6.67 M
Answer: Option (b) is the correct answer.
Explanation:
In material bonding, there occurs Vander waal foces between the molecules in which their is either an induced or permanent dipole moment that attract molecules towards each other.
And, due to these forces the molecules are held together.
On the other hand, in a ionic bond there will always be transfer of electrons from one atom to another. This is because on atom which loses its valence electrons acquires a positive charge and another atom which gains the electrons acquires a negative charge.
Hence, these opposite charges strongly gets attracted towards each other forming a strong bond.
Whereas in a covalent bond, there will be sharing of electrons between the combining atoms.
In a metallic bond, there occurs a sea of electrons which is uniformly distributed throughout the solid substance or material.
Thus, we can conclude that the statement, Van der Waals bonds are formed by Van der Waals forces in which molecules or atoms have either an induced or permanent dipole moment to attract each other, about material bonding is correct.