Answer:
b) 3.10
Explanation:
HF ⇄ H
+ + F
Using Henderson-Hasselbalch Equation:
pH = pKa + log [A-]/[HA].
Where;
pKa = Dissociation constant = -log Ka
Hence, pKa of HF = -log 7.2 x 10^-4 = 3.14266
[A-] = concentration of conjugate base after dissociation = moles of base/total volume
= 0.15 x 0.3/0.8
= 0.05625 M
[HA] = concentration of the acid = moles of acid/total volume
= 0.10 x 0.5/0.8
= 0.0625 M
Note: <em>Total volume = 500 + 300 = 800 mL = 0.8 dm3</em>
pH = 3.14266 + log [0.05625/0.0625]
= 3.14267 + (-0.04575749056)
= 3.09691250944
<em>From all the available options below:</em>
<em>a) 2.97
</em>
<em>b) 3.10
</em>
<em>c) 3.19
</em>
<em>d) 3.22
</em>
<em>e) 3.32</em>
The correct option is b.
1) Dalton stated that atom is matter that can not be divided, but it is proved that the atom can be divided into subatomic particles (electrons, protons and neutrons).
2) He stated that atoms of one element can not be changed into atoms of other elements, but now that is possible by nuclear reactions.
Today we still use his postulate: Atoms combine in the ratio of small whole numbers to form stable compounds, for example H₂O.
Answer:
1. A circuit is a path that electricity flows along. It starts at a power source, like a battery, and flows through a wire to a light bulb or other object and back to other side of the power source.
2. A series circuit is one that has more than one resistor, but only one path through which the electricity (electrons) flows. All the components in a series circuit are connected end-to-end. A resistor in a circuit is anything that uses some of the power from the cell.
3. A parallel circuit is a circuit in which the electric current passes through two or more branches or connected parts at the same time before it combines again. Compare.
4. BOTH - 1. lightbulb 2. battery 3. switch
SERIES- 1. Ammeter 2. voltmeter
i'm not sure about the rest sorry :(
NaBrO3 is the chemical formula for Sodium Bromate.
