Answer : The correct option is, (4) 6.0 mol
Explanation :
The given balanced chemical equation is,
In this reaction, lead undergoes reduction and chromium undergoes oxidation.
Oxidation reaction : It is the reaction in which a substance looses its electrons. In this oxidation state increases.
Reduction reaction : It is the reaction in which a substance gains electrons. In this oxidation state decreases.
Half reactions of oxidation-reduction are :
Oxidation : 
Reduction : 
From the reduction reaction, we conclude that 6 moles of electrons gained by the 3 moles of lead ions.
Hence, the correct option is, (4) 6.0 mole
5.27 kJ of heat are required to heat 231 g of gold from 18 °C to 195 °C.
We have 231 g of gold at 18 °C and supply it with heat to increase its temperature to 195 °C. We can calculate the amount of heat required using the following expression.
where,
- <em>c: specific heat capacity of gold</em> (0.129 J/g.°C)
- ΔT: change in the temperature
5.27 kJ of heat are required to heat 231 g of gold from 18 °C to 195 °C.
You can learn more about heating here: brainly.com/question/1105305
Answer:
In 1897, the British physicist J. J. Thomson (1856–1940) proved that atoms were not the most basic form of matter. He demonstrated that cathode rays could be deflected, or bent, by magnetic or electric fields, which indicated that cathode rays consist of charged particles (Figure 2.2.2 ). More important, by measuring the extent of the deflection of the cathode rays in magnetic or electric fields of various strengths, Thomson was able to calculate the mass-to-charge ratio of the particles. These particles were emitted by the negatively charged cathode and repelled by the negative terminal of an electric field. Because like charges repel each other and opposite charges attract, Thomson concluded that the particles had a net negative charge; these particles are now called electrons. Most relevant to the field of chemistry, Thomson found that the mass-to-charge ratio of cathode rays is independent of the nature of the metal electrodes or the gas, which suggested that electrons were fundamental components of all atoms.
Explanation:
