Crystal water

The chemist wanted to check the content of water of crystallization of chromic potassium alum K₂SO₄ * Cr₂ (SO₄) 3 * 24 H₂O, which was a long time in the laboratory. From 96.8 g of K₂SO₄ * Cr₂ (SO₄) 3 * 24 H₂O prepared 979 cm³ solution of base. Subsequently, the 293 cm³ of the stock solution, a solution of barium nitrate, and a precipitate precipitated weighing 19.6 g.

How many crystal water instead of 24 molecules contain salt?
             
Additional data to compute:
M (K₂SO₄ * Cr₂ (SO₄) 3 * 24 H₂O) = 998.2 g / mol, M(BaSO₄) = 233.4 g / mol
M(K₂SO₄ * Cr₂ (SO₄) 3) = 566.2 g / mol, M (H₂O) = 18 g / mol


Correct result:

x =  546.2 g

Solution:

$x=546.2={\displaystyle \frac{2731}{5}}\text{ g}=546.2\text{ g}$

Try another example

Showing 0 comments:

Next similar math problems:

• Remainders
  It is given a set of numbers { 170; 244; 299; 333; 351; 391; 423; 644 }. Divide this numbers by number 66 and determine set of remainders. As result write sum of this remainders.
• Four prisms
  Question No. 1: The prism has the dimensions a = 2.5 cm, b = 100 mm, c = 12 cm. What is its volume? a) 3000 cm² b) 300 cm² c) 3000 cm³ d) 300 cm³ Question No.2: The base of the prism is a rhombus with a side length of 30 cm and a height of 27 cm. The heig
• Annual income
  The annual incomes (in thousands of $) of fifteen families is: 60, 80, 90, 96, 120, 150, 200, 360, 480, 520, 1060, 1200, 1450, 2500, 7200 Calculate harmonic and geometric mean.
• Chess
  How many ways can select 4 fields on classic chess board with 64 fields, so that fields don't has the same color?
• Statistics
  The sum of all deviations from the arithmetic mean of the numerical sequence 4, 6, 51, 77, 90, 93, 95, 109, 113, 117 is:
• City market
  Apples were sold at contractual prices at the city market. Calculate the average price of 1 kg of apples sold: Stand, Sale kg, Price CZK/kg 1 325 6.20 2 194 7.00 3 258 6.50 4 870 5.90 5 275 6.40
• Average height
  In a class are 34 students. The average height of the students is 165 cm. What will be the average height of students in the classroom when two pupils, tall 176 cm and 170 cm, moved from this school/class?
• Center of gravity
  The mass points are distributed in space as follows - specify by coordinates and weight. Find the center of gravity of the mass points system: A₁ [1; -20; 3] m₁ = 46 kg A₂ [-20; 2; 9] m₂ = 81 kg A₃ [9
• Three elephants
  Three elephants eat three piles of hay in 150 minutes. For how long does 96 elephants eat  96 stacks of hay?
• Complaints
  The table is given: days complaints 0-4 2 5-9 4 10-14 8 15-19 6 20-24 4 25-29 3 30-34 3 1.1 What percentage of complaints were resolved within 2weeks? 1.2 calculate the mean number of days to resolve these complaints. 1.3 calculate the modal number of day
• Rotary cylinder
  In the rotary cylinder it is given: surface S = 96 cm² and volume V = 192 cm cubic. Calculate its radius and height.
• Crystal
  The crystal grows every month 1.2 permille of its mass. For how many months to grow a crystal from weight 177 g to 384 g?
• A photograph
  A photograph will stick to a white square letter with a x cm length. The photo is 3/4 x cm long and 20 cm wide than the width of the paper. The surface of the remaining paper surrounding the photograph is 990 cm². Find the size of paper and photo.
• Acid solution
  By adding 250 grams of a 96% solution of sulfuric acid to its 3% solution its initial concentration was changed to 25%. How many grams of 3% of the acid were used for dilution?
• Basic form
  Expressed the ratios of values in the basic form: 0,5 t : 1,2 kg 200 l : 0,15 m³ 12 t : 3600 kg 500 kg : 2,5 t 0,9 kg : 500 g 3,6 m : 240 cm 1200 mm : 2,4 m 300 l : 0,3 m³ 6 min 30 s : 900 s
• Divisible by 5
  How many three-digit odd numbers divisible by 5, which are in place ten's number 3?
• Dataset:
  Dataset: 35 22 18 54 22 46 28 31 43 22 14 17 25 19 33 14. 1 Group the data into a grouped distribution using 6 classes of equal width. 2. Determine the mean, median and mode using the raw data. 3. Draw an Ogive curve corresponding to the data and use it t