Answer:
C) Highly reactive
Explanation:
An atom with one or two valence electrons more than a closed shell is highly reactive, because the extra valence electrons are easily removed to form a positive ion
<span>the average atomic mass of this element is 39.95 u</span>
Answer the correct option will be option B.
Explanation: this is how he showed the electron could orbit the nucleus without falling into it. This is so because he explained that the electron revolves around the nucleus in a fixed circular orbit with fixed energy and cannot occupy just any energy level which is defined as quantisation of energy.
option A is one of postulates given by Dalton in his Dalton's atomic theory which later proved to be wrong.
option C it is one of the postulates given by the in J.J Thomson in his model of an atom which was the first atomic model.
option D Schrodinger has used the wave nature to explain the position of electrons around the nucleus.
Answer: To calculate the enthalpy of combustion of acetylene, C2H2 , all you have to do is ... More specifically, you need to subtract from the sum of enthalpies of ... chemical reaction has 2 moles of C2H2 reacting to produce 2 moles of ... since the heat of combustion is expressed as energy per mole
I think the reaction that is occurring is CuSO₄(aq)+Na₂CO₃(aq)⇒CuCO₃(s)+Na₂SO₄(aq). Water in the hydrate will just become part of water in solution so it does not really matter for this question.
SInce we now know the balanced chemical equation, you can use stoichiometry to find the amount of reactants needed to produce 5g CuCO₃.
The first step to any stoichiometry question is to convert the mass given into moles. To do this you have to divide the mass by the molar mass of the compound the mass is referring to. The molar mass of CuCO₃ is 123.5g/mol so you have to divide 5g by 123.5g/mol to get 0.04047 moles of CuCO₃.
The next step in this qustoin is to find the number of moles of each reactant using the moles of product we found in the first step. To do this, we need go back and look at the equation to find the molar ratios which is shown through the coefficients. Since all of the coeficients in the chemical equation is 1, we know the molar ratios are all `1 to 1 and therefore the number of moels of each reactant is equal to the number of moles of the product found in step one. This means that you started off with 0.04047 moles of both CuSO₄ and Na₂CO₃.
The final step is to multiply the number moles of each reactant by its molar mass. the molar mass of CuSO₄ is 159.6g/mol and the molar mass of Na₂CO₃ is 106g/mol. When you multiply 0.04047mol by 159.6g/mol you get 6.4g and when you multiply 0.04047mol by 106g/mol you get 4.29g.
Therefore you started with 6.4g of CuSO₄ and 4.29g of Na₂CO₃.
I hope this helps.
