Answer:
5.0g/cm^3
Explanation:
Since we have the mass of the wood (25.0g) and the volume of the wood (5.0cm^3), can use the formula for density to answer this question.
Density=mass/density
Density=25.0g/5.0cm^3
Density=5.0g/cm^3
Therefore, the density of the piece of wood is 5.0g/cm^3.
I hope this helps!
Hi, the question has some missing part. The complete question should be " If the 
of 
is 3.74 and the pH of an 
solution is 3.89, it means that -
(a) ![[HCHO_{2}]=[NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3D%5BNaCHO_%7B2%7D%5D)
(b) ![[HCHO_{2}]> [NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3E%20%5BNaCHO_%7B2%7D%5D)
(c) ![[HCHO_{2}]< [NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3C%20%20%5BNaCHO_%7B2%7D%5D)
Which of the options are true?"
Answer: Option (c) is true.
Explanation:
is an weak acid-conjugate base buffer. Hence, in accordance with Henderson-Hasselbalch equation-
![pH=pK_{a}(HCHO_{2})+log(\frac{[CHO_{2}^{-}]}{[HCHO_{2}]})](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28HCHO_%7B2%7D%29%2Blog%28%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D%29)
Here, pH = 3.89, of = 3.74
So, ![3.89=3.74+log(\frac{[CHO_{2}^{-}]}{[HCHO_{2}]})](https://tex.z-dn.net/?f=3.89%3D3.74%2Blog%28%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D%29)
or, ![\frac{[CHO_{2}^{-}]}{[HCHO_{2}]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D)
= 1.41 (>1)
So, ![[CHO_{2}^{-}]> [HCHO_{2}]](https://tex.z-dn.net/?f=%5BCHO_%7B2%7D%5E%7B-%7D%5D%3E%20%5BHCHO_%7B2%7D%5D)
or, ![[NaCHO_{2}]> [HCHO_{2}]](https://tex.z-dn.net/?f=%5BNaCHO_%7B2%7D%5D%3E%20%5BHCHO_%7B2%7D%5D)
Hence, option (c) is correct.
Answer:
Mass percent concentration: 25,2% m/m
Explanation:
The percentage mass by mass indicates the grams of solute in 100 grams of solution. We convert the ml of water into g from the density formula:
δ= m/v m=δx v= 1 g/ml x 115 ml= 115 g
115g solution-----29 g NaCl
100g solution----x=(100g solutionx29 g NaCl)/115g solution
x=25,2173913 g NaCl
There are 2 valence elcetrons
Answer:
i believe the answer is B.
Explanation :
Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun.
