Answer: An initial velocity
Explanation:
First, we determine the mass of stearic acid in the solution by multiplying the given concentration by the volume.
mass of stearic acid = (5.4 x 10^-4 g/L) (0.25 mL) (1000 mL/1L)
= 0.135 g
Then, we divide this amount by the molar mass in order to obtain the number of moles of stearic acid. The molar mass of stearic acid is 284.4772 g/mol.
moles stearic acid = 0.135 g / (284.4772 g/mol)
= <em>4.75 x 10^-4 mol</em>
<span>It changes with new evidence.
The example shows that science changes with new evidence. Science can not change with common beliefs because first of all beliefs should be proved and become evidence. Second, science is not fixed because of the scientific method and experimentation, which is a phase of the scientific method.
</span>
Answer:
1.95g of Mg(OH)2 are needed
Explanation:
Mg(OH)2 reacts with HCl as follows:
Mg(OH)2 + 2 HCl → MgCl2 + 2H2O
<em>Where 1 mole of Mg(OH)2 reacts with 2 moles of HCl</em>
To solve this question we must find the moles of acid. Then, with the chemical equation we can find the moles of Mg(OH)2 and its mass:
<em>Moles HCl:</em>
158mL = 0.158L * (0.106mol / L) = 0.01675 moles HCl
<em>Moles Mg(OH)2:</em>
0.01675 moles HCl * (2mol Mg(OH)2 / 1mol HCl) = 0.3350 moles Mg(OH)2
<em>Mass Mg(OH)2 -Molar mass: 58.3197g/mol-</em>
0.3350 moles Mg(OH)2 * (58.3197g / mol) =
<h3>1.95g of Mg(OH)2 are needed</h3>
