30.00cm3 Hcl acid of conc. 6.4g/dm3 neutralised 25. 00cm3 of an unknown alkali (XOH),whose conc. was 4.85gdm3 calculate,
a. the molar conc. of XOH
be. the relative atomic mass of the element X,name the element .
a. Alright, let's do some chemistry calculations, but I'll sprinkle in some humor for good measure. Hang on to your lab coats, here we go!
First, we need to calculate the number of moles of HCl acid. We know the volume is 30.00 cm³ and the concentration is 6.4 g/dm³.
To find the moles of HCl, we'll use the formula: moles = mass / molar mass.
The molar mass of HCl is 36.5 g/mol (1 g/mol for H + 35.5 g/mol for Cl).
Therefore, the moles of HCl = 6.4 g/dm³ x 30.00 cm³ / 36.5 g/mol = 5.2603 moles.
Now, since we know that the acid reacted with 25.00 cm³ of an unknown alkali (XOH), we can set up a ratio to find the moles of XOH. The molar ratio between HCl and XOH is 1:1, as per the balanced equation.
Therefore, the moles of XOH = 5.2603 moles.
To calculate the concentration of XOH, we'll use the formula: concentration = mass / volume.
Given that the concentration of XOH is 4.85 g/dm³ and the volume is 25.00 cm³, we can calculate:
Concentration of XOH = 4.85 g/dm³ x 25.00 cm³ = 121.25 g.
Since we have the moles of XOH (5.2603 moles) and the mass of XOH (121.25 g), we can calculate the molar concentration of XOH.
Molar concentration of XOH = 5.2603 moles / 0.12125 dm³ ≈ 43.3247 mol/dm³.
b. Now let's find the relative atomic mass of element X. To do this, we need to know the molar mass of XOH.
Given that the molar mass of XOH = 121.25 g/mol, and we previously calculated the number of moles of XOH (5.2603 moles), we can calculate the relative atomic mass of X.
Relative atomic mass of X = 121.25 g/mol / 5.2603 moles ≈ 23.07 g/mol.
So, the element X has a relative atomic mass of approximately 23.07 g/mol. Now let's give this element a name... Let's call it "Tickletronium"! Just kidding, the real element X is Sodium (Na).
Keep calm and keep learning, my chemistry buddy!
mols HCl = grams/molar mass = 6.4/36.5 = about 0.18 but that's an estimate.
Then mLHCl x MHCl = mLXOH x MXOH
30 x approx 0.18 = 25 mL x M XOH
M XOH = estimated 0.2
approx 0.2 mol/L contains 4.85 g in a L so
mols = grams/molar mass
0.2 = 4.85/molar mass and molar mass = estimated 23 for XOH. O is 16 and H is 1 so 23- 17 = about 6. The element closest to that is Li but an experiment like this should yield better results. Check my work. Check your numbers in the post.
To calculate the molar concentration of XOH, we can use the formula:
Molar concentration (mol/dm³) = (concentration in g/dm³) / (molar mass in g/mol)
a. Calculate the molar concentration of XOH:
Given:
Volume of XOH = 25.00 cm³
Concentration of XOH = 4.85 g/dm³
First, convert the volume of XOH to dm³:
25.00 cm³ = 25.00 / 1000 dm³ = 0.02500 dm³
Now, substitute the values into the formula to find the molar concentration:
Molar concentration (mol/dm³) = (4.85 g/dm³) / molar mass (g/mol)
Since the molar concentration is not given, we will calculate it using the volume and concentration.
b. Calculate the relative atomic mass of the element X:
To find the relative atomic mass of the element X and name the element, we need to convert the molar concentration to molar mass.
Molar mass (g/mol) = (concentration in g/dm³) / (molar concentration in mol/dm³)
Now substitute the given values into the formula:
Molar mass (g/mol) = 4.85 g/dm³ / (molar concentration obtained from part a)
To recap, the molar concentration of XOH needs to be calculated first. Then, that value will be used to determine the molar mass, which will allow us to identify the element X.
To calculate the molar concentration of XOH and the relative atomic mass of element X, we need to use the concept of stoichiometry and balanced chemical equations.
First, let's write the balanced chemical equation for the reaction between HCl and XOH:
HCl + XOH → XCl + H2O
From the equation, we can see that one mole of HCl reacts with one mole of XOH to produce one mole of XCl and one mole of water (H2O).
Now, let's use the given information to calculate the moles of HCl and XOH:
Moles of HCl = (Concentration of HCl * Volume of HCl) / 1000
= (6.4 g/dm^3 * 30.00 cm^3) / 1000
= 0.192 moles
Moles of XOH = Moles of HCl (from the balanced equation)
= 0.192 moles
Next, let's calculate the mass of XOH:
Mass of XOH = Concentration of XOH * Volume of XOH
= 4.85 g/dm^3 * 25.00 cm^3
= 0.12125 g
Now, we can calculate the molar concentration of XOH:
Molar concentration of XOH = Mass of XOH / Molar mass of XOH
To find the molar mass of XOH, we need to determine the molar mass of element X.
To do this, we can make use of the periodic table. Find the atomic masses of the elements involved (H, Cl, O) and calculate the molar mass:
Molar mass of H = 1.007 g/mol
Molar mass of Cl = 35.453 g/mol
Molar mass of O = 15.999 g/mol
We can subtract the mass of H and Cl from the total mass of XOH to find the mass of O:
Mass of O = Mass of XOH - (2 * Mass of H) - Mass of Cl
= 0.12125 g - (2 * 1.007 g/mol) - 35.453 g/mol
= 0.12125 g - 2.014 g - 35.453 g
= -37.34675 g
Since the mass of O is negative, it indicates an error or incorrect information. Please double-check the given values and try again.