Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object.
1.the chemical change color from colorless to purple
2. A yellow gas forms
3.a brown solid forms in the bottom of the beaker
4.the temperature of the chemicals rises 15 Celsius
Explanation:
All of the options are proofs that chemical change has occurred.
A chemical change is one with the following properties:
- A new kind of matter is usually formed as seen by the gas evolution and the formation of the insoluble precipitate i.e brown solid at the bottom of the beaker.
- They are not easily reversible.
- Usually accompanied by energy changes as seen in the rise in temperature.
- Color changes can also infer chemical changes in a reaction.
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Answer:
Iron is the densest out of the given options.
Explanation:
Oxygen
1.429 g/L
Water
1000 g/L
Hydrogen Peroxide
1450 g/L
Iron
7874 g/L
Iron Oxide
5240 g/L
Molarity is a unit of concentration defined as the number of moles of solute (the substance being dissolved) per volume of solution (the solvent in which all the solute is dissolved). Mathematically, molarity is expressed as
.
In this question, we are given the molarity and the volume of a solution of NaCl. We can use this information to calculate the number of moles of NaCl present in the solution. Rearranging the equation to solve for moles of solute, we multiply the molarity by the volume of the solution (the units for volume must be in liters, so 125 mL is expressed as the equivalent 0.125 L):
The question asks for the number of moles of NaCl in this solution, so number 3 would be correct.
Answer:
The answer to your question is pH = 3
Explanation:
Data
[H⁺] = 1 x 10⁻³
pH = ?
pH is a measure of the hydrogen concentration. It measures the acidity or alkalinity. The range of pH goes from 0 to 14. The pH for an acid is from 0 to 6.9, for a neutral solution is 7.0 and for an alkali is from 7.1 to 14.
Formula
pH = -log [H⁺]
-Substitution
pH = -log [1 x 10⁻³]
-Simplification
pH = - (-3)
-Result
pH = 3
