B. When scientific understanding changes.
Answer:
science is good U will be a genius
2.54 × 10⁵ kJ of heat are required to fully melt a 0.834 m³ block of ice, with a density of 917 kg / m³.
<h3>What is melting?</h3>
Melting is a physical change in which solids turn into liquids.
- Step 1. Calculate the mass of ice.
We have a block of 0.834 m³ of ice with a density of 917 kg/m³.
0.834 m³ × 917 kg/m³ = 765 kg = 7.65 × 10⁵ g
- Step 2. Convert 7.65 × 10⁵ g to moles.
We will use the molar mass of water.
7.65 × 10⁵ g × (1 mol/18,02 g) = 4.24 × 10⁴ mol
- Step 3. Calculate the heat required to melt 4.24 × 10⁴ moles of water.
According to the thermochemical equation, 6.01 kJ are required to melt 1 mol of water.
4.24 × 10⁴ mol × (6.01 kJ/mol) = 2.54 × 10⁵ kJ
2.54 × 10⁵ kJ of heat are required to fully melt a 0.834 m³ block of ice, with a density of 917 kg / m³.
Learn more about melting here: brainly.com/question/40140
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Answer:
a) Single displacement reaction
b) Decomposition reaction
c) Double displacement reaction
d) Precipitation reaction
Explanation:
(a) 
In this reaction, oxygen is replaced by C, so it is a type of displacement reaction. Here, only one species is being replaced, therefore, it is a single displacement reaction.
(b) 
In this reaction, potassium chlorate decomposes to potassium chloride and oxygen, so it is a type of decomposition reaction.
(c) 
In this reaction, chloride and OH- ions are being replaced. so, it is a type of double decomposition reaction.
(d) 
In this reaction, 
is precipitated, so it is a type of precipitation reaction.
I'm assuming you're asking how to test for a starch,
To do so you do this thing called the "Iodine Test"
The potassium iodide aqueous solution will form this complex with starch to form a purplish-blue color.
However, watch out for the pH as hydrolysis of starch could occur to prevent the test from working out-- and the temperature as the greater it is, the less intense the color is
