The is D because Search ResultsFeatured snippet from the webValence Shell Electron Pair Repulsion (VSEPR) theory Electron pairs around a central atom arrange themselves so that they can be as far apart as possible from each other. ... The repulsion between negatively charged electron pairs in bonds or as lone pairs causes them to spread apart as much as possible.

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3 C2H2(g) → C6H6(g) What is the standard enthalphy change ΔHo, for the reaction represented above? (ΔHof of C2H2(g) is 230 kJ mo The standard enthalpy change is -607kJ


The given balanced chemical reaction is,


First we have to calculate the enthalpy of reaction



-" alt="\Delta H^o=-" align="absmiddle" class="latex-formula">


We are given:


Putting values in above equation, we get:

-<(3\times 230)>=-607kJ" alt="\Delta H^o_rxn=<(1\times 83)>-<(3\times 230)>=-607kJ" align="absmiddle" class="latex-formula">

The standard enthalpy change is -607kJ

O Group 7A, Period 4


To find the location of bromine on the periodic table, we must known its period and group on the periodic table.

Bromine is made up of 35 electrons.

Its electronic configuration is:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁵

From this configuration, the number of energy levels here is 4 so the element bromine is in period 5

Since the number of valence electrons is 7, it belongs to group 7

So, period 4 and group 7 is the right choice

1090 mmHg


We know that with gases we must use Kelvin temperatures, so let’s try a plot of pressure against the Kelvin temperature.

We can create a table as follows

t/°C T/K p/mmHg

10 283 726

20 293 750

40 313 800

70 343 880

100 373 960

150 423 ???

I plotted the data and got the graph in the figure below.

It appears that pressure is a linear function of the Kelvin temperature.

y = mx + b

where x is the slope and b is the y-intercept.

Calculate the slope

I will use the points (275, 700) and (380, 975).

Slope = Δy/Δx = (975 -700)/(380 – 275) = 275/105 = 2.619


y = 2.619x + b

Calculate the intercept

When x = 275, y = 700.

700 = 2.619 × 275 + b

700 = 720 + b Subtract 720 from each side and transpose.

b = -20

So, the equation of the graph is

y = 2.619x -20

Calculate the pressure at 423 K (150°C)

y = 2.619 × 423 -20

y = 1110 -20

y = 1090

At 150 °C, the pressure 1090 mmHg.

The point is approximately at the position of the black dot in the graph.

See more: How Many Protons And Neutrons Does Lithium Have ? How Many Protons Does Lithium Ion Have

3 0
4 months ago
Offspring, or young, ______ to look like their parents, but are ___ the ________.
faltersainse <42>

Tend. Similar. Parents. (sorry if it"s wrong. It"s kinda confusing on the last 2 words. Make it more clearer pls to get a better


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11 months ago
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