How many significant figures<br> are in this number?<br> 3.80 x 10^-4

In the laboratory, Austin is given a mixture of iron filings, sand, and salt. To separate the mixture, Austin uses a magnet, boi

Alex_Xolod [135]

Answer:

D

Explanation:

7 0

3 years ago

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An interpenetrating primitive cubic structure like that of CsCl with anions in the corners has an edge length of 664 pm. If the

san4es73 [151]

Answer:

the ionic radius of the anion $r^- = 312.52 \ pm$

Explanation:

From the diagram shown below :

The anion $Cl^-$ is located at the corners

The cation $Cs^+$ is located at the body center

The Body diagonal length = $\sqrt{3 \ a }$

∴ $2 \ r^+ \ + 2r^- \ = \sqrt{3 \ a} \\ \\ r^+ +r^- = \frac{\sqrt{3}}{2} a$

Given that :

$\frac{r^+}{r^-} =0.84$ (i.e the ratio of the ionic radius of the cation to the ionic radius of

the anion )

$0.84r^- \ + r^- \ = \frac{\sqrt{3}}{2}a \\ \\ 1.84 r^- = \frac{3}{2}a \\ \\ r^- = \frac{\sqrt{3}}{2*1.84}a$

Also ; a = 664 pm

Then :

$r^- = \frac{\sqrt{3} }{2*1.84}*664 \ pm\\ \\ r^- = 312.52 \ pm$

Therefore, the ionic radius of the anion $r^- = 312.52 \ pm$

4 0

3 years ago

The percent composition of nh42c2o4

zzz [600]

Answer: Percent composition by element

Element Symbol Mass Percent

Hydrogen H 6.498%

Carbon C 19.357%

Nitrogen N 22.574%

Oxygen O 51.571%

HOPE THIS HELPS

5 0

3 years ago

Consider the reaction. 2c(s,graphite) h2= c2h2(g) Based on the equation and the information in the table, what is the enthalpy o

xxTIMURxx [149]

<h3>The enthalpy of the reaction : C.226.73 kJ</h3><h3>Further explanation</h3>

Delta H reaction (ΔH) is the amount of heat change between the system and its environment

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)

The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation

Delta H reaction (ΔH) is the difference between product enthalpy and reactant enthalpy (Hp-Hr)

Reaction :

2C + H2 -> C2H2

(ΔH) reaction = (ΔH) product - (ΔH) reactants

(ΔH) reaction = (ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

for free element (ΔH) it has zero value, so (ΔH) C and (ΔH) H2 have zero value

From the available data: Hf (kJ / mol) C2 H2 (g)= 226.73

then

(ΔH) reaction = ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

(ΔH) reaction = 226.73 - (0 + 0)

(ΔH) reaction = 226.73 (answer C)

<h3>Learn more</h3>

(ΔH) reaction

brainly.com/question/1889660

Keywords : (ΔH) reaction, C2H2

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3 years ago

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Arkeisha and Rodney are having a discussion about the correct use of the term "battery acid." Arkeisha insists that an alkaline

mote1985 [20]

Arkeisha is correct because the fluid in an alkaline battery has a ph between 7.1 and 14.0

8 0

4 years ago

How many significant figures are in this number? 3.80 x 10^-4