Answer:
13) 3.9
14) 12000
15) 6800
16) 110
17) 0.00049
18) 120
Explanation:
First we will look at the second digit of given values.
we will draw a line after second digit then we will look the digit after line.
It the digit after line which is 3rd digit is 5 or more than 5 then one will be added to the second digit.
It it is less than five then second digit remain same.
After this we will add zeros to the right till decimal point.
13) 3.948
Round to two significant figures = 3.9
14) 11561.06
Round to two significant figures = 12000
15) 6789.2
Round to two significant figures = 6800
16) 112.6
Round to two significant figures = 110
17) 0.00048888
Round to two significant figures = 0.00049
18) 119.999
Round to two significant figures = 120
MgSO4 + 2NaOH —> Mg(OH)2 + Na2SO4
Answer:
13.5 * 10^-2 g
Explanation:
What we know:
Balanced Equation: 3Ba+Al2(SO4)3 -->2Al+3BaSO4,
Grams of Ba: 1
Grams of Al2(SO4)3: 1.8g
Calculate the # of moles of Ba and Al2(SO4)3:
1g Ba/137.3 = 7.3 *10^-3 mol Ba
1.8g Al2(SO4)3/ 342 = 5.3 *10^-3 mol Al2(SO4)3
Find the limiting reactant:
Ba has a coefficient of 3 in the balanced equation, so we divide the # of moles of Ba by 3 to get... 7.3 *10^-3 mol Ba/3 = 2.43 *10^-3
Al2(SO4)3 has a coefficient of 1, so if we divide by 1, we get the same number of 5.3 *10^-3
2.43 *10^-3 is smaller than 5.3 *10^-3, therefore Ba is the limiting reactant.
finally, we just find the number of moles of Al
The ratio of Al to Ba is 2:3 so...
7.3 * 10^-3 * (2/3) = 5 *10^-3 mol Al
CONVERT TO GRAMS
5 *10^-3 mol Al * 27 = 13.5 * 10^-2 g
<u>Hope that was helpful! </u>
Answer:
C
Explanation:
C is the best answer. The endocrine system releases and controls hormones, which are basically just signals sent through the body.
These hormones regulate homeostasis, which is how your body stays at regular levels / stays the same. It keeps your body at steady conditions.