Molality can be expressed by moles of solute over
kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl
is equal to 0.25 moles of NaCl over 1 kg of water.
The balanced reaction equation for the combustion of butane is as follows;
C₄H₁₀ + 13/2O₂ ---> 4CO₂ + 5H₂O
the limiting reactant in this reaction is C₄H₁₀ This means that all the butane moles are consumed and amount of product formed depends on the amount of C₄H₁₀ used up.
stoichiometry of C₄H₁₀ to H₂O is 1:5
mass of butane used - 6.97 g
number of moles - 6.97 g / 58 g/mol = 0.12 mol
then the number of water moles produced - 0.12 mol x 5 = 0.6 mol
Therefore mass of water produced - 0.6 mol x 18 g/mol = 10.8 g
In photograph a, a coil of zinc metal is in a solution of sulfuric acid. In photograph b, a yellow solution of sodium chromate is being added to a colorless solution of silver nitrate. What clues in the photographs indicate that a chemical change is probably occurring.
In photograph a, chemical change is occuring as when a coil of zinc metal is in a solution of sulfuric acid, then the solution starts bubbling, that indicates a chemical change.
In photograph b, a yellow solution of sodium chromate is being added to a colorless solution of silver nitrate, that changes the color of the solution to red , that indicates a chemical change.
Answer:
1.12x10²³ atoms of F
Explanation:
A molecule is a group of 2 or 3 atoms that are bonded by electrostatic charges.
In 1 molecule of MgF2 there are 2 atoms of fluorine and 1 atom of magnesium.
Thus, there are 2 atoms of fluorine per molecule of MgF2. In 5.6x10²² molecules:
5.6x10²² molecules MgF2 * (2 atoms Fluorine / 1 molecule MgF2) =
<h3>1.12x10²³ atoms of F</h3>
The flask would break, the flare would drop and the ether would light on fire.
