Answer:
potassium (K) and bromine (Br)
Explanation:
- Periodic table is a table of elements in terms of rows and columns in terms of their chemical and physical properties.
- Elements in the same group or columns have similar physical and chemical properties. For example, elements in the same group have the same number of valence electrons or valency.
- Elements in the same period or rows have similar number of energy levels. For example, potassium and bromine belong to the same period in the periodic table and thus have the same number of energy levels.
Answer:
![m_{H_2O}=9.24gH_2O](https://tex.z-dn.net/?f=m_%7BH_2O%7D%3D9.24gH_2O)
Explanation:
Hello there!
In this case, since there is a 2:2 mole ratio between sodium peroxide and water according to the given reaction, it is possible to apply the following stoichiometric setup for the calculation of the required mass of water:
![m_{H_2O}=40.0gNa_O_2*\frac{1molNa_O_2}{78gNa_O_2}*\frac{2molH_2O}{2molNa_O_2} *\frac{18.02gH_2O}{1molH_2O} \\\\m_{H_2O}=9.24gH_2O](https://tex.z-dn.net/?f=m_%7BH_2O%7D%3D40.0gNa_O_2%2A%5Cfrac%7B1molNa_O_2%7D%7B78gNa_O_2%7D%2A%5Cfrac%7B2molH_2O%7D%7B2molNa_O_2%7D%20%20%2A%5Cfrac%7B18.02gH_2O%7D%7B1molH_2O%7D%20%5C%5C%5C%5Cm_%7BH_2O%7D%3D9.24gH_2O)
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Answer is: it takes 116,8 seconds to fall to one-sixteenth of its initial value
<span>
The half-life for the chemical reaction is 29,2 s and is
independent of initial concentration.
c</span>₀
- initial concentration the reactant.
c - concentration of the reactant remaining
at time.
t = 29,2 s.<span>
First calculate the rate constant k:
k = 0,693 ÷ t = 0,693 ÷ 29,2 s</span> = 0,0237 1/s.<span>
ln(c/c</span>₀) = -k·t₁.<span>
ln(1/16 </span>÷ 1) = -0,0237 1/s ·
t₁.
t₁ = 116,8 s.
Answer:
In the physical sciences, a phase is a region of space, throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, magnetization and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, an
Explanation:
Hope this helps :)
Answer:
1= 2H₂ + O₂ → 2H₂O
2=CaCo₃ + heat → CaO +CO₂
3=CH₄ + 2O₂ → CO₂ +2H₂O
4=HCl + NaOH → NaCl + H₂O
Explanation:
1 = Simple composition
The formation of water molecule is simple composition reaction. In this reaction two hydrogen atoms react with one oxygen atom and form one water molecules.
2H₂ + O₂ → 2H₂O
The amount of energy released is -285.83 KJ/mol. It is exothermic reaction.
2 = Simple decomposition reaction:
The break down of calcium carbonate into calcium oxide and carbondioxide is decomposition reaction. The decomposition reactions re mostly endothermic, because compound required energy to break.
CaCo₃ + heat → CaO +CO₂
3 = Combustion reaction
Consider the combustion of methane:
CH₄ + 2O₂ → CO₂ +2H₂O
The burning of methane is exothermic. The combustion reactions are exothermic because when fuel are burns they gives energy.
4 = Neutralization reaction
The neutralization reactions are those in which acid and base react to form the salt and the water. Some neutralization reactions are exothermic because they release heat. e.g
Consider the neutralization reaction of HCl and NaOH.
HCl + NaOH → NaCl + H₂O