Answer:
Below 0° degrees Celcius
Explanation:
For deposition (gas to solid) to happen, the temperature has to be below 0° Celsius. If so, deposition occurs, and ice crystals form.
The reaction is of order three with respect to the reactant.
<h3>Explanation</h3>
The rate of a reaction of order n about a certain reactant is proportion to the concentration of that reactant raised to the n-th power. This is true only if concentrations of any other reactants stay constant in the whole process.
In other words, Rate = constant × [Reactant]ⁿ, Rate ∝ [Reactant]ⁿ. (The symbol "∝" reads "proportional to".)
In this question,
[4 × Reactant]ⁿ ÷ [Reactant]ⁿ = 64.
In other words, 4ⁿ = 64, where n is the order of the reaction with respect to this reactant.
It might take some guesswork to find the value of n. Alternatively, n can be solved directly with a calculator using logarithms. Taking natural log of both sides:
.
Evaluating 
on Google or on a calculator with support for ln (the natural log) will give the value of n- no guesswork required.
n = 3. Therefore, the reaction is of order three with respect to this reactant.
Elements are substances that cannot be separated into simpler substances. Salt is made up of the elements sodium and chloride. Water is made up of the elements hydrogen and oxygen.
The smallest particles of matter are called atoms. Remember the carrot from the other chapter. If you continue to chop a carrot into smaller and smaller pieces, eventually you would reach a point where you could not cut up the carrot anymore, but still have carrot. You would then have molecules of carrot. The same applies to elements. If you continually cut up a piece of aluminum, you will reach a point that you could no longer divide it. These are aluminum atoms. An atom is the smallest particle of an element that has the properties of that element. Some properties of aluminum are: shiny, silver colored, fragile, and thin. Each element has its own type of properties.
Chemists use symbols to represent elements. A symbol is a letter or picture used to represent something. Chemists use one or two lettters to represent elements. The symbol for aluminum is Al. The symbol for oxygen is O.
Answer:
9.03 x 10²³atoms
Explanation:
Given parameters:
Number of moles of CO₂ = 1.5mol
Unknown:
Number of atoms = ?
Solution:
In a mole of a substance, we have the Avogadro's number of particles which is 6.02 x 10²³atoms.
Using this number, we can determine the amount of atoms in any substance.
If;
1 mole of CO₂ contains 6.02 x 10²³ atoms;
1.5mole of CO₂ will contain 1.5 x 6.02 x 10²³ atoms
= 9.03 x 10²³atoms
Answer:
0.01395mol Cr2O3
Explanation:
the molar mass of Cr2O3 is 151.9904 g/mol
2.12g Cr2O3 x 1 mol/151.9904g = 0.01395mol Cr2O3
