There are 3 possible ways of determining pH.
1. A pH meter, 2. Litmus paper/ pH test strips or 3. Titrations.
1. A pH meter works by sending a small electric current through the solution. An electrical current can only be created if there are free-moving particles such as H+ ions from an acid or OH- ions from a base. The pH meter can determine the pH by how high the conductivity is.
2. Litmus Paper or pH test strips are strips that turn a specific colour under a specific pH. This colour can then be compared to a colour chart which will tell you the pH. The downfall of this method is that the red ink will stain the strip and you will be unable to get an accurate reading.
3. A titration is the best method, if done properly, for determining pH.
Using the law of constant proportions which says that within the same compound, elements exist in fixed ratios.
Therefore; we can use the ratio of total mass to the mass of carbon, to determine the amount of carbon in another sample.
Mass C / Mass CH4 = Mass C / Mass CH4
43.2 g / 57.6 g = Mass C / 37.8 g
Mass C = 37.8 g × 43.2 g / 57.6 g
= 28.35 g
Hence; the percentage of carbon will be;
=(28.35/ 37.8 )× 100%
= 75 %
Thus; 75% of 37.8 g of methane is carbon
Answer is (4) - Se.
Among the given choices Se has the highest electronegativity value as 2.4 compared to others. Hence, Se shows <span>greatest attraction for electrons in a chemical bond.
</span>Electronegativity is
a value that tells us how an atom can attract electrons towards itself. <span>If
the electronegativity is high, then the attraction to the electrons is also high.
</span>
Answer:
0.5059kg
Explanation:
The heat absorbed for the water is determined using the equation:7
Q = C×m×ΔT
<em>Where Q is heat absorbed (4300cal)</em>
<em>C is specific heat (1cal/g°C)</em>
<em>m is the mass in grams</em>
<em>ΔT is change in °C (101.0°C - 92.5°C = 8.5°C)</em>
<em />
Replacing:
4300cal = 1cal/g°C×m×8.5°C
505.9g = m
In kg, the mass of water is:
<h3>0.5059kg</h3>
<em />
Answer:
Explanation:
Question 6 options:
1)
A single replacement reaction takes place because sodium is less reactive than hydroxide ions.
