You would also need to know the mol of sodium. After knowing the mol, write down the reaction;
Na + H20 -> NaOH + H2
Use the mol ratio, to find the amount of mol of sodium hydroxide. (Remember to balance the equation first)
After you have the necessary variables, use the following formula:
mass of sodium hydroxide = mol of sodium hydroxide x molar mass (relative/formula mass of sodium hydroxide)
That is how you will find the mass of sodium hydroxide.
You input potential (stored<span>) </span>energy<span> into the </span>rubber band<span> system when you </span>stretched<span> the</span>rubber band<span> back. Because it is an </span>elastic<span> system, this kind of potential </span>energy<span> is specifically </span>called elastic<span> potential </span>energy<span>. ... When the </span>rubber band<span> is released, the potential </span>energy<span> is quickly converted to kinetic (motion) </span>energy<span>.</span>
<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>
<em>Hello there, and thank you for asking your question here on brainly.
The answer to this is Answer choice C: CaCl2
</em>Hope this helped you! ♥<em>
</em>
