A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
Hopefully that helps you ❤
Answer:
R = V / I
Explanation:
Ohm's Law:
V = I * R , V = voltage , I = current , R = resistance
rearranging to solve R,
R = V / I
<span>1. What is the colour of FeSO4.7H20 crystals?How does this colour change upon heating?
</span><span>Melanterite or FeSO4.7H20 is green in color
</span>2FeSO4 ---> Fe2O3 + SO2 + SO3<span>
2. a. What are redox reactions?
It </span><span>is a type of chemical </span>reaction<span> that involves a transfer of electrons between two species.
</span><span>
b.Why is the reaction between MnO2 and HCl a
redox reaction?
Because there are atoms that are reduced and are oxidized.
c.Identify the substance oxidized and the
substance reduced in the above reaction.
</span>MnO2<span> + 4 </span>HCl<span> ---> MnCl2 + 2H2O + Cl2
</span>Mn was reduced and Cl was oxidized
To find pH, use the following formula ---> pH= - log [H+]
so first we need to calculate the [H+] concentration using the OH concentration. to do this, we need to use this formula--> 1.0x10-14= [H+] X [OH-], so we solve for H+ and plug in
[H+]= 1.0X10-14/[OH-]---> 1.0 x 10-14/ 1.0 x 10-4= 1.0 x 10-10
now that we have the H+ concentration, we can solve of pH
pH= -log (1.0x10-10)= 10
answer is A
