Answer:
- 0.71963 g of Zn
- 0.80256 g of HCl
Step-by-step explanation:
The required mass of reactants can be computed from the number of moles of product.
moles of ZnCl₂ = (1.5 g)/(136.282 g) ≈ 0.0110066 moles
Then the mass of Zn required is ...
mass of Zn = (0.0110066 mol)(65.382 g/mol) = 0.71963 g
Two moles of HCl are used in the reaction with each mole of Zn, so the mass of HCl required is ...
mass of HCl = 2(0.0110066 mol)(36.458 g/mol) = 0.80256 g
_____
<em>Comment</em>
The discrepancy in the last two decimal places of the weights above versus the calculator output below comes from rounding of moles of Zn to 4 significant digits, instead of 5 or more. The number of moles of ZnCl₂ is closer to 0.0110066.
Answer:
The correct answer is: 360.
Explanation:
First we can express 120 as follows:
2 * 2 * 2 * 3 * 5 = 120
You can get the above multiples as follows:
120/2 = 60
60/2 =30
30/2 = 15
15/3 = 5 (Since 15 cannot be divisible by 2, so we move to the next number)
5/5 = 1
Take all the terms in the denominator for 120, you would get: 2 * 2 * 2 * 3 * 5 --- (1)
Second we can express 360 as follows:
360/2 = 180
180/2 = 90
90/2 =45
45/3 = 15 (Since 45 cannot be divisible by 2, so we move to the next number)
15/3 = 5
5/5 = 1
Take all the terms in the denominator for 360, you would get: 2 * 2 * 2 * 3 * 3 * 5 --- (2)
Now in (1) and (2) consider the common terms once and multiple that with the remaining:
2*2*2*3*5 = Common between the two
3 = Remaining
Hence (2*2*2*3*5) * (3) = 360 = LCM (answer)
Answer:
D.
Step-by-step explanation:
In order to eliminate, the numbers must eliminate. If the second equation is multiplied by 3, then the 3 and the -3 can be eliminated. Since it is multiple choice, we can plug in x = 12 and y = 10 to see if they are correct. 12 + 30 = 42 and 24 - 10 = 14, so D is correct.
Answer: x = $7, y = $6
Step-by-step explanation:
Let x be the cost of an adult ticket
Let y be the cost of a children's ticket
Translate these sentences to algebra:
At the circus, three adult tickets and five child tickets cost $51: 3x + 5y = 51
Five adult tickets and two child tickets cost $47: 5x + 2y = 47
Now we have two equations. Let's use substitution to solve.
3x + 5y = 51
3x = 51 - 5y
.: x = 17 - 5y/3
Now substitute this value of x into the second equation to find the numerical value of y:
5(17 - 5y/3) + 2y = 47
85 - 25y/3 + 2y = 47
-19y/3 = -38
-19y = -114
.: y = 6
Now find x:
x = 17 - 5y/3
x = 17 - 10
.: x = 7
So an adult ticket costs $7, and a child ticket costs $6 :)
Answer:
a. x > 0.2
Step-by-step explanation:
In either order, subtract the left-side constant and divide by the x-coefficient.
3x +2.4 > 3
3x > 0.6 . . . . . . subtract 2.4
x > 0.2 . . . . . . . divide by 3
__
or
x + 0.8 > 1 . . . . divide by 3
x > 0.2 . . . . . . . subtract 0.8
