<span>85% ethanol | 25% ethanol | 50% ethanol
x | y | 20 gal
use x and y because you don;t know how much she needs.
0.85x | 0.25y | 20(0.5)
85% is 85/100 or 0.85, and you need that much of x, same goes for the 25% and 50% mixtures so now you can make up 2 equations
1) x + y = 20 2) 0.85x + 0.25y= 10 (you get 10 when you multiply 20 by 0.5) now you can solve for x or y using substitution.
first rewrite 1) in terms of x or y: x+ y= 20 ----> y= 20 - x now you can substitute 20- x for y in the second equation.. 0.85x + 0.25y= 10 0.85x + 0.25(20-x)= 10 distribute here..(0.25 * 20 and 0.25 * (-x) ) 0.85x + 5 - 0.25x = 10 combine like terms 0.6x +5 = 10 move the 5 over to the other side 0.6x= 10 -5 0.6x = 5 divide both sides by 0.6 x= 25/3 or 8.3 now you know the amount of x so you can substitue this back into the first equation to find y. 0.85x + 0.25y= 10 0.85(25/3) +0.25y= 10 85/12 + 0.25y= 10 0.25y = 10- 85/12 0.25y= 35/12 y= 35/3 or 11.6 you can check by putting these values into the euations: 1) x+ y= 20 25/3 + 35/3 =20 20= 20 good so far 2) 0.85x + 0.25y= 10 0.85(25/3) + 0.25(35/3)=10 10 = 10
so our values for x and y work
x= 25/3 and y= 35/3</span>
Answer:
%age Yield = 34.21 %
Explanation:
The balance chemical equation for the decomposition of KClO₃ is as follow;
3 KOH + H₃PO₄ → K₃PO₄ + 3 H₂O
Step 1: Calculate moles of H₃PO₄ as;
Moles = Mass / M/Mass
Moles = 334.6 g / 97.99 g/mol
Moles = 3.414 moles
Step 2: Find moles of K₃PO₄ as;
According to equation,
1 moles of H₃PO₄ produces = 1 moles of K₃PO₄
So,
3.414 moles of H₃PO₄ will produce = X moles of K₃PO₄
Solving for X,
X = 1 mol × 3.414 mol / 1 mol
X = 3.414 mol of K₃PO₄
Step 3: Calculate Theoretical yield of K₃PO₄ as,
Mass = Moles × M.Mass
Mass = 3.414 mol × 212.26 g/mol
Mass = 724.79 g of K₃PO₄
Also,
%age Yield = Actual Yield / Theoretical Yield × 100
%age Yield = 248 g / 724.79 × 100
%age Yield = 34.21 %
The daughter isotope : Radon-222 (Rn-222).
<h3>Further explanation</h3>
Given
Radium (Ra-226) undergoes an alpha decay
Required
The daughter nuclide
Solution
Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
- alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles ₀γ⁰
- positron particles ₁e⁰
- neutron ₀n¹
The decay reaction uses the principle: the sum of the atomic number and mass number before and after decay are the same
Radium (Ra-226) : ₈₈²²⁶Ra
Alpha particles : ₂⁴He
So Radon-226 emits alpha α particles ₂He⁴ , so the atomic number decreases by 2, mass number decreases by 4
The reaction :
₈₈²²⁶Ra ⇒ ₂⁴He + ₈₆²²²Rn
Answer:
120mph
Explanation:
Google
divide the speed value by 1.467
or
176 times 60 second in a minute times 60 minutes in an hour
than divide by 5280 the amount of feet in a mile
Answer:
1461.7 g of AgI
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
CaI₂ + 2AgNO₃ —> 2AgI + Ca(NO₃)₂
From the balanced equation above,
1 mole of CaI₂ reacted to produce 2 moles of AgI.
Next, we shall determine the number of mole AgI produced by the reaction of 3.11 moles of CaI₂. This can be obtained as follow:
From the balanced equation above,
1 mole of CaI₂ reacted to produce 2 moles of AgI.
Therefore, 3.11 moles of CaI₂ will react to produce = 3.11 × 2 = 6.22 moles of AgI
Finally, we shall determine the mass of 6.22 moles of AgI. This can be obtained as follow:
Mole of AgI = 6.22 moles
Molar mass of AgI = 108 + 127
= 235 g/mol
Mass of AgI =?
Mass = mole × molar mass
Mass of AgI = 6.22 × 235
Mass of AgI = 1461.7 g
Therefore, 1461.7 g of AgI were obtained from the reaction.
