The atomic mass number does<span> not change because a </span>beta<span> particle has a much smaller </span>mass<span> than the </span>atom<span>. The </span>atomic number<span> goes up because a neutron has turned into an extra proton. </span>Beta decay<span> is fundamentally different from alpha </span>decay<span>. An alpha particle is made of two protons and two neutrons.</span>
Yes the answer is true as long as it combines physically and not chemically to form the new substance which would then called a mixture.
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Answer:
The answer to your question is 3.5 moles of H₂
Explanation:
Data
moles of H₂ = ?
moles of Zn = 3.5 moles
moles of HCl = excess
Process
1.- Write the balanced chemical reaction
Zn + 2HCl ⇒ ZnCl₂ + H₂
Reactants Elements Products
1 Zn 1
2 Cl 2
2 H 2
2.- Use the coefficients of the balanced reaction to calculate the moles of H₂
1 mol of Zn ----------------- 1 mol of H₂
3.5 moles of Zn ------------- x
x = (3.5 x 1)/1
x = 3.5 moles of H₂
It's quite hard to explain without an example, but I'll give it a go:
Basically, you have to count the number of an element on one side of the equation, then count it on the other, and the aim of balancing the equation is to get the 2 values to be the same (as mass cannot be created or destroyed).
This involves multiplication of the molecule(s) on either side of the equation in order to balance the whole thing. Note this is not like maths, you dont have to do the same to both sides, but you <em>do</em> have to multiply out <em>entire molecules</em> - you cannot multiply just the H2 in H2O for example.
A reasonably basic example of this balancing is:
Fe + Cl2 = FeCl3
The first thing I notice is that there is an even number of Cl atoms on the left, and an odd number on the right, so the first thing I'll do is multiply the one on the right to get it to an even number, ie by 2.
Fe + Cl2 = 2(FeCl3)
Expanding that gives Fe2Cl6 (although you dont write it like that). So we need to get 6 Cl atoms and 2 Fe atoms by multiplying the left hand molecules by amounts if possible. If you look at that, we can achieve that, by multiplying Cl2 by 3, and Fe by 2.
2Fe + 3Cl2 = 2FeCl3
And there you have your balanced equation, you'll notice that the number of any given element has the same number of atoms on both sides of the equation.
The chemical symbol for sodium bicarbonate is NaHCO₃. Its molar mass is calculated by adding the product of the molar mass of each of the component and the number of moles. That is,
molar mass of NaHCO₃ = (1 mol Na)(23 g Na/1 mol Na) + (1 mol H)(1 g H/ 1 mol H) + (1 mol C)(12 g C/1 mol C) + (3 mol O)(16 g O/1 mol O)
molar mass of NaHCO₃ = 84 g/mol
Same is to be done with sodium carbonate which has a molar mass of Na₂CO₃
molar mass of Na₂CO₃ = (2 mol Na)(23 g Na/1 mol Na) + (1 mol C)(12 g C/1 mol C) + (3 mol O)(16 g O/1 mol O)
molar mass of Na₂CO₃ = 106 g/mol
The decomposition of sodium bicarbonate to sodium carbonate is shwon below,
2NaHCO₃ --> Na₂CO₃ + H₂O + CO₂
Through conversion factors and dimensional analysis,
(1.678 g NaHCO₃)(1 mol NaHCO₃/84 g NaHCO₃)(1 mol Na₂CO₃/2 mol NaHCO₃)(106 g NaHCO₃/1 mol NaHCO₃)
= 1.06 g Na₂CO₃
<em>ANSWER: 1.06 g Na₂CO₃</em>