The polarity of a water molecule
comes from the uneven distribution of electron density of hydrogen and oxygen
atom. The oxygen in the water molecule is more electronegative than the
hydrogen. Water has a partial positive charge near the hydrogen atom and a
partial negative charge near the oxygen atom. The result of this
electrostatic attraction results in the bond called hydrogen bond. Also,
because of this bond, it has the ability to dissolve most of the solutes due to
its polarity and bonding.
Answer:
2.5×10^-7mol/dm^3
Explanation:
Firstly convert the cm^3 to dm^3
200×1000=200000dm^3
Calculate the g/dm^3
2/200000=0.00001g/dm^3
To calculate mol/dm^3
Mol/dm^3=mass given\molar mass
=0.00001/40
=2.5×10^-7mol/dm^3
Answer:
The correct option is: b. pH 6.4-8.0
Explanation:
Phenol red is a weak acid that is used as a pH indicator and exists in the form of stable red crystals.
<u>The color of the phenol red solution changes from yellow to red when the change in pH is observed. The color of phenol red transitions from yellow to red when the pH is 6.8 - 8.2 or 6.4 - 8.0</u>
Above the pH of 8.2, the phenol red solution turns a bright pink in color.
Answer:
1.3×10²³ formula unit
Explanation:
Given data:
Mass of CaCl₂ = 23.8 g
Number of formula unit = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 23.8 g/110.98 g/mol
Number of moles = 0.21 mol
1 mole of any substance contain 6.022×10²³ formula unit
0.21 mol × 6.022×10²³ formula unit / 1mol
1.3×10²³ formula unit
Answer:
37.1g are produced
Explanation:
The combustion of C₈H₁₈ is:
C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O
<em>Where 1 mole of C₈H₁₈ produce 8 moles of CO₂</em>
<em />
To find the mass of CO₂ that is produced we need to convert the mass of C₈H₁₈ with molar mass. Then, with the chemical equation, we can find the moles of CO₂ and its mass, as follows:
<em>Moles C₈H₁₈ -Molar mass: 114.2g/mol-</em>
12g C₈H₁₈ * (1mol / 114.2g) = 0.105 moles of C₈H₁₈
<em>Moles CO₂:</em>
As 1 mole of C₈H₁₈ produce 8 moles of CO₂, 0.105 moles of C₈H₁₈ produce:
0.105 moles of C₈H₁₈ * (8moles CO₂ / 1mole C₈H₁₈) = 0.84 moles of CO₂
<em>Mass CO₂ -Molar mass: 44.01g/mol-:</em>
0.84 moles of CO₂ * (44.01g / mol) = 37.0g of CO₂ ≈
<h3>37.1g are produced</h3>
