What is 155.4g÷8.70mL, rounded to the correct number of significant figures

butalik [34]

Can you show the question that goes with those answer pls

7 0

2 years ago

The elements found in Group 2A, from top to bottom, include beryllium, magnesium, calcium, strontium, and barium. Which of these

elena-14-01-66 [18.8K]

Electronegativity is the property of the element to attract electrons to its nucleus. The trend of electronegativity in the periodic table is decreasing from right to left and decreasing from top to bottom. hence from the given elements, the element with the highest electronegativity should be A.beryllium

5 0

3 years ago

Read 2 more answers

During a hot summer, air temperatures along a coastline are higher above the land than they are above the water, even though bot

mars1129 [50]

Over the ocean, the temperature rises much slower, because the water evaporates causing the hot molecules to go into the atmosphere, and the overall temperature of the water doesn't increase much, this causes the area without the water to be much hotter.

6 0

2 years ago

Your brain and spinal cord are joined to the other parts of your body through __________.

Lostsunrise [7]

Answer is A

You never run down adjacent to you spinal cord and bones. That’s where they are the most protected. There are also holes in the pelvis bone for nerves to pass through

5 0

2 years ago

Gallium is produced by the electrolysis of a solution made by dissolving gallium oxide in concentrated NaOH ( aq ) . Calculate t

Sedbober [7]

Answer:

Approximately $6.30\times 10^{-3}\;\rm mol$ .

Explanation:

The gallium here is likely to be produced from a $\rm NaGaO_2\, (aq)$ solution using electrolysis. However, the problem did not provide a chemical equation for that process. How many electrons will it take to produce one mole of gallium?

Note the Roman Numeral " $\mathtt{(III)}$ " next to $\rm Ga$ . This numeral indicates that the oxidation state of the gallium in this solution is equal to $+3$ . In other words, each gallium atom is three electrons short from being neutral. It would take three electrons to reduce one of these atoms to its neutral, metallic state in the form of $\rm Ga\, (s)$ .

As a result, it would take three moles of electrons to deposit one mole of gallium atoms from this gallium $\mathtt{(III)}$ solution.

How many electrons are supplied? Start by finding the charge on all the electrons in the unit coulomb. Make sure all values are in their standard units.

$t = \rm 80.0\; min = 80.0\; min \times 60\;s \cdot min^{-1} = 4800\; s$ .

$Q = I \cdot t = \rm 0.380 \; A \times 4800 \; s = 1.824\times 10^3\; C$ .

Calculate the number of electrons in moles using the Faraday's constant. This constant gives the size of the charge (in coulombs) on each mole of electrons.

$\begin{aligned} n(\text{electrons}) &= \frac{Q}{F} \cr &= \rm \dfrac{1.824\times 10^3\; C}{96485.332\; C \cdot mol^{-1}}\cr &\approx \rm 1.89\times 10^{-2}\; mol \end{aligned}$ .

It takes three moles of electrons to deposit one mole of gallium atoms $\rm Ga\, (s)$ . As a result, $\rm 1.89\times 10^{-2}\; mol$ of electrons would deposit $\displaystyle \rm \frac{1}{3}\times 1.89\times 10^{-2}\; mol \approx 6.30\times 10^{-3}\; mol$ of gallium atoms $\rm Ga\, (s)$ .

8 0

2 years ago