Answer:
homogeneous
Explanation :
<span>composed of parts or elements that are all of the same kind; not heterogeneous. Uneven and fixed are out of the subject and do not make since.</span>
2 HBr + Mg(OH) 2 yields Mg(Br) 2 + 2 H2O
M1V1 = M2V2
(0.245 M)(37.5 mL) = (M2)(18.0 mL)
9.1875 = (M2)(18.0 mL)
9.1875/(18.0 mL) = (M2)(18.0 mL)/(18.0 mL)
0.51041
this is not the complete answer as the mol to mol ratio must be considered!
For every 2 mols of HBr there is 1 mole of <span>Mg(OH)2; ratio = 2:1
</span>0.51041 / 2 = 0.25520
M2 = 0.25520
0.25520 M of<span> Mg(OH)2 solution</span>
Answer:
It will take 6.6 hours for 75% of the lead to decay.
Explanation:
The radioactive decay follows first order rate law
The half life and rate constant are related as
The rate law for first order reaction is
![time=\frac{1}{k}(ln[\frac{A_{0}}{A_{t}}]](https://tex.z-dn.net/?f=time%3D%5Cfrac%7B1%7D%7Bk%7D%28ln%5B%5Cfrac%7BA_%7B0%7D%7D%7BA_%7Bt%7D%7D%5D)
Where
A0 = initial concentration = 1 g
At= final concentration = 0.25 g (as 75% undergoes decay so 25% left]
So in a chemical change, the product would loses its properties, would form new products and would not be easily reversed.
In a physical change, the products WILL NOT lose any of their properties, WILL NOT form any new products and WILL be easily reversed.
Talking about Water turning to ice I would say it’s all about physical change and not chemical change.
But I would suggest you to either make a research about it or ask your teacher :))
A change that alters the identity of a substance resulting in a new substance or substances with different properties. A change to a substance that occurs without forming a new substance, such as a change in size or state of matter.
