I believe it would be the transformation of electrical energy to heat energy, and the transformation of heat energy and then the heat to the bread
Answer:
Q1. D) A single replacement reaction takes place because sodium is more reactive than hydrogen.
Explanation: 
Sodium metal reacts with water to givesodium hydroxide and hydrogen gas. A single replacement reaction takes place because sodium is more reactive than hydrogen.
Sodium easily lose electrons than hydrogen and get oxidized to 
and 
get reduced to give 
.
Q2. B) It is a single replacement reaction, and the cations in the two ionic compounds are different.
Explanation: 
where Sodium is a metal and 
is an ionic compound. Na being more reactive than Al, displaces it from its salt solution.
Q3. D) 
Explanation: A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.Thus zinc can easily lose electrons as compared to hydrogen and result in the formation of zinc sulfate and hydrogen.
Q4. False
no reaction
Explanation: As zinc lies lower in reactivity series, it is less reactive than calcium. It will not be able to displace calcium from its salt and hence no reaction occur. Thus the given statement is false.
Q5. False
Explanation: A double displacement reaction is one in which exchange of ions take place. Thus an element replaces another element and not same element.
A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.
Q6. A)
, because K retains the same charge throughout the reaction
Explanation: A balanced chemical reaction is one in which the number of atoms on both sides of a chemical equation are same. Also K has an oxidation state or charge of +1 in 
as well as 
Answer:
115060 J
Explanation:
From the question given above, the following data were obtained:
Mass (M) = 500 g
Initial temperature (T1) = 20 °C
Final temperature (T2) = 75 °C
Change in temperature (ΔT) = 55 °C
Specific heat capacity (C) = 4.184 J/g°C
Heat (Q) required =?
The heat required to change the temperature of the water can obtained as follow:
Q = MCΔT
Q = 500 × 4.184 × 55
Q = 115060 J
Therefore, the heat needed to change the temperature of the water is 115060 J.
Answer:
Mass of sodium hydroxide needed = 28.2 g
Explanation:
Given data:
Mass of sodium hydroxide = 80 g
Mass of sodium sulfate produced = 142 g
Mass of sodium hydroxide needed = ?
Mass of sodium sulfate produced = 50 g
Solution:
Mass of sodium sulfate produced / Mass of sodium hydroxide = Mass of sodium sulfate produced / x
142 g/ 80 g = 50 g / x
x = 50 g × 80 g / 142 g
x =4000 g/ 142
x = 28.2 g
Answer:
A) The mass would be the same.
Explanation:
Since there is no loss of any particle to vapor during the phase change process from solid to liquid, the mass of the before and after the process will remain the same.
- In this way, the law of conservation of mass is obeyed.
- Mass is the amount of matter contained in a substance.
- Since there is no room for escape or matter loss, the mass will remain the same.
