The Rock Cycle<span> is a group of changes. Igneous </span>rock<span> can change into sedimentary </span>rock<span> or into metamorphic </span>rock<span>. Sedimentary </span>rock<span> can change into metamorphic </span>rock<span> or into igneous </span>rock<span>. Metamorphic </span>rock<span> can change into an igneous or sedimentary </span>rock<span>. Igneous </span>rock<span> forms when magma cools and makes crystals.</span>
I believe the statement that is true of metals and metalloids is B. Metals are good conductors and metalloids are bad conductors.
Answer:
40:1 is the ratio of the magenta phenolphthalein concentration to the colorless phenolphthalein concentration.
Explanation:
To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:
![pH=pK_a+\log(\frac{[salt]}{[acid]})](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%29)
![pH=pK_a+\log(\frac{[magenta(Php)]}{[Php]})](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%28%5Cfrac%7B%5Bmagenta%28Php%29%5D%7D%7B%5BPhp%5D%7D%29)
We are given:
= negative logarithm of acid dissociation constant of phenolphthalein = 9.40
![[magenta(Php)]](https://tex.z-dn.net/?f=%5Bmagenta%28Php%29%5D)
= concentration of magenta phenolphthalein
![[Php]](https://tex.z-dn.net/?f=%5BPhp%5D)
= concentration of colorless phenolphthalein
pH = 11
Putting values in above equation, we get:
![11=9.40+\log(\frac{[magenta(Php)]}{[Php]})](https://tex.z-dn.net/?f=11%3D9.40%2B%5Clog%28%5Cfrac%7B%5Bmagenta%28Php%29%5D%7D%7B%5BPhp%5D%7D%29)
![\log(\frac{[magenta(Php)]}{[Php]})=11-9.40=1.6](https://tex.z-dn.net/?f=%5Clog%28%5Cfrac%7B%5Bmagenta%28Php%29%5D%7D%7B%5BPhp%5D%7D%29%3D11-9.40%3D1.6)
![\frac{[magenta(Php)]}{[Php]}=10^{1.6}=39.81 :1 \approx 40:1](https://tex.z-dn.net/?f=%5Cfrac%7B%5Bmagenta%28Php%29%5D%7D%7B%5BPhp%5D%7D%3D10%5E%7B1.6%7D%3D39.81%20%3A1%20%5Capprox%2040%3A1)
40:1 is the ratio of the magenta phenolphthalein concentration to the colorless phenolphthalein concentration.
PH is the scale of measurement to check either the solution is acidic or basic. if the pH value is greater than 7, the solution is towards basicity and if the pH value is less than 7, the solution is towards acidity.
pKa is the dissociation constant and it is used to describe the change in pH value, when pKa is equal to pH: 50% of the ionizable group is protonated and 50% of the enzymes will be active.
So 50% of the enzymes will be active.
Explanation:
if they aren't in a solvent, then you magnetize first, to remove the iron fillings, secondly, you can sieve to separate the sand and pebbles
