If you have a magnesium for every oxygen, then you have to start with two magnesiums. So the balanced equation is 2 Mg + O2 2 MgO.
And
CaCO3———→CaO + CO2
I hope it helped!
Ca(OH)₂ ==> Ca²⁺ + 2 OH<span>-
Ca(OH)</span>₂ is <span>strong Bases</span><span>
</span>Therefore, the [OH-] equals 5 x 10⁻⁴ M. For every Ca(OH)₂ you produce 2 OH⁻<span>.
</span>
pOH = - log[ OH⁻]
pOH = - log [ <span>5 x 10⁻⁴ ]
pOH = 3.30
pH + pOH = 14
pH + 3.30 = 14
pH = 14 - 3.30
pH = 10.7
hope this helps!</span>
Decomposition is a chemical reaction that breaks the reactant into two or more products. Moles of nitrogen gas
in the cylinder is 1.63 moles.
<h3>What is the ideal gas equation?</h3>
The ideal gas equation states the relation of the hypothetical ideal gas according to the pressure, volume, temperature and moles of the gas. It is given by,

Where,
Pressure (P) = 2000 kPa
Volume (V) = 2L
Temperature (T) = 295 K
Gas constant (R)= 0.08206
Substituting values in the equation:

Therefore, 1.63 moles are produced.
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The value of ΔG° at this temperature is -18034.18 J/mol
Calculation,
Given information
formation constant (Kf)= 1.7 × 
Universal gas constant (R) = 8.314 J/K• mol
Temperature = 25° C = 25 °C + 273 = 300 K
Formula used:
ΔG° = -RT㏑Kf
By putting the valur of R,T, Kf we get the value of ΔG°
ΔG° = - 8.314 J/K• mol×300K㏑ 1.7 × 
ΔG° = -2494.2㏑ 1.7 ×
= -18034.18 J/mol
So, change in standard Gibbs's free energy is -18034.18 J/mol
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This problem is asking for the percent by mass of hydrogen in hydrofluoric acid. At the end, the answer turns out to be D. 5% as shown below:
<h3>Percent compositions:</h3>
In chemistry, percent compositions are used for us to know the relative amount of a specific element in a compound. In order to do so for hydrogen, we use the following formula, which can also be applied to any other element in a given compound:

Where
stands for the atomic mass of hydrogen and
for the molar mass of hydrofluoric acid. In such a way, we plug in the atomic masses of hydrogen (1.01 g/mol) and fluorine (19.0 g/mol) to obtain:

Learn more about percent compositions: brainly.com/question/12247957