Explanation:
When we move across a period from left to right then there will occur an increase in electronegativity and also there will occur an increase in non-metallic character of the elements.
As calcium (Ca) is a group 2A element and rubidium (Rb) is a group 1A element. Hence, Rb being an alkali metal is more metallic in nature than calcium (alkaline earth metal).
Both magnesium (Mg) and radium (Ra) are group 2A elements. And, when we move down a group then as the size of element increases so, it becomes easy of the metal atom to lose an electron.
As a result, there occurs an increase in metallic character of the element. Hence, Radium (Ra) is more metallic in nature than magnesium (Mg).
Also, both bromine and iodine are group 17 elements. Since, both of them are non-metals and non-metallic character increases on moving down the group.
Therefore, bromine (Br) is more metallic than iodine.
Answer:
The molality of the KCl solution is 11.8 molal
Explanation:
Step 1: Data given
Mol fracrion KCl = 0.175
Molar mass KCl = 74.55 g/mol
Molar mass H2O = 18.02 g/mol
Step 2: Calculate mol fraction H2O
mol fraction H2O = 1 - 0.175 = 0.825
Step 3: Calulate mass of H2O
Suppose the total moles = 1.0 mol
Mass H2O = moles H2O * molar mass
Mass H2O = 0.825 * 18.02 g/mol
Mass H2O = 14.87 grams = 0.01487 kg
Step 4: Calculate molality
Molality KCl = 0.175 / 0.01487 kg
Molality KCl = 11.8 molal
The molality of the KCl solution is 11.8 molal
Answer:
3.336.
Explanation:
<em>Herein, the no. of millimoles of the acid (HCOOH) is more than that of the base (NaOH).</em>
<em />
So, <em>concentration of excess acid = [(NV)acid - (NV)base]/V total</em> = [(30.0 mL)(0.1 M) - (29.3 mL)(0.1 M)]/(59.3 mL) = <em>1.18 x 10⁻³ M.</em>
<em></em>
<em> For weak acids; [H⁺] = √Ka.C</em> = √(1.8 x 10⁻⁴)(1.18 x 10⁻³ M) = <em>4.61 x 10⁻⁴ M.</em>
∵ pH = - log[H⁺].
<em>∴ pH = - log(4.61 x 10⁻⁴) = 3.336.</em>
Example:
Mass = ?
Density = 25 g/mL
Volume = 5 mL
therefore:
d = m / V
25 = m / 5
m = 25 x 5
m = 125 g
hope this helps!
Answer:
answer. the measure. is f=90 the equbaliint is 180
Explanation:
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