To the top. Common knowledge my dude. Heat always rises to the top.
Answer:
a) 65.74 = 4 significant figures
b) 60.009 = 5 significant figures
c) 66_ = 2 significant figures
d) 65.750 = 5 significant figures
Explanation:
Significant figures or digits is defined as the total number of digits in a number that have meaning and contribute to the precision of the given number.
a) 65.74 = 4 significant figures, all the non-zero figures are considered significant.
b) 60.009 = 5 significant figures, zeros present between non-zero figures are significant.
c) 66_ = 2 significant figures, all the non-zero figures are considered significant.
d) 65.750 = 5 significant figures, all the non-zero figures and the trailing zero after the decimal are significant.
Solution :
![pk_b = -log ( K_b)\\\\pk_b = - log ( 3.6 \times 10^{-5})\\\\pk_b = 4.44](https://tex.z-dn.net/?f=pk_b%20%3D%20-log%20%28%20K_b%29%5C%5C%5C%5Cpk_b%20%3D%20-%20log%20%28%203.6%20%5Ctimes%2010%5E%7B-5%7D%29%5C%5C%5C%5Cpk_b%20%3D%204.44)
We know, pH of this solution :
![pH = pK_a + log ( \dfrac{|conjugate\ base|}{|weak \ acid|}\\\\pH = 4.44 + log(\dfrac{0.480}{0.190})\\\\pH = 4.44 + 0.40\\\\pH =4.84](https://tex.z-dn.net/?f=pH%20%3D%20pK_a%20%20%2B%20log%20%28%20%5Cdfrac%7B%7Cconjugate%5C%20base%7C%7D%7B%7Cweak%20%5C%20acid%7C%7D%5C%5C%5C%5CpH%20%3D%204.44%20%2B%20log%28%5Cdfrac%7B0.480%7D%7B0.190%7D%29%5C%5C%5C%5CpH%20%3D%204.44%20%2B%200.40%5C%5C%5C%5CpH%20%3D4.84)
Hence, this is the required solution.
Answer:
2. Ag
Explanation:
A cathode gains electrons therefore electrons are reduced. Silver (Ag) is a stronger oxidising agent than magnesium.
Explanation:
- Polar molecule are soluble in polar solvents
- Non polar molecules are soluble in non polar solvents.
Stearic acid is an organic acid composed of seventeen carbons with one carboxylic acid group in the end. Its chemical formula is
. The hydrophobic part is this chain is made up of 17 carbon atom and hydrophilic part is only of made up of carboxylic group due to which it won't get dissolve in water.Which means that stearic acid will get dissolve in non polar solvent that is hexane. Hence, stearic acid is non polar molecule.
Where as sucrose an organic molecule with molecular formula of
.Due to presence of polar hydroxyl(-OH) groups in molecule , molecule will get easily dissolve in polar solvent that is water. Since,the hydrophobic part in the molecules are covered by the hydrophilic part due to which it gets easily dissolve in water. Hence, the sucrose in polar molecule.