<h2>5060 have three significant figures : Explanation given below </h2>
Explanation:
Significant figures
The significant figures (also known as the significant digits and decimal places) of a number are digits that possess certain meaning .
It includes all digits except: zeros
Rules to find significant figures
1.All non-zero digits are considered significant. For example, 23 has two significant figures.
2.Zeros in between two non-zero digits are significant: like in 202.1201 has seven significant figures.
3.Zeros to the left of the significant figures are not significant. For example, .000021 has two significant figures, zeros have no value .
4.Zeros to the right of the significant figures are significant.
That is the reason in number 5060 , it has 3 significant figures .
Q1. A.
Q2. Nitrous oxide
Hope this helped ♥︎
It is a mixture. it can easily be separated.
I don't know what the options were but a material that is very likely going to be challenging to recognize under a microscope as a mixture is a homogeneous mixture. A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!
Answer:
pH = 13.09
Explanation:
Zn(OH)2 --> Zn+2 + 2OH- Ksp = 3X10^-15
Zn+2 + 4OH- --> Zn(OH)4-2 Kf = 2X10^15
K = Ksp X Kf
= 3*2*10^-15 * 10^15
= 6
Concentration of OH⁻ = 2[Ba(OH)₂] = 2 * 0.15 = 3 M
Zn(OH)₂ + 2OH⁻(aq) --> Zn(OH)₄²⁻(aq)
Initial: 0 0.3 0
Change: -2x +x
Equilibrium: 0.3 - 2x x
K = Zn(OH)₄²⁻/[OH⁻]²
6 = x/(0.3 - 2x)²
6 = x/(0.3 -2x)(0.3 -2x)
6(0.09 -1.2x + 4x²) = x
0.54 - 7.2x + 24x² = x
24x² - 8.2x + 0.54 = 0
Upon solving as quadratic equation, we obtain;
x = 0.089
Therefore,
Concentration of (OH⁻) = 0.3 - 2x
= 0.3 -(2*0.089)
= 0.122
pOH = -log[OH⁻]
= -log 0.122
= 0.91
pH = 14-0.91
= 13.09
