Calculate and give the answer with the correct number of significant
figures.
3.256 / 2.7

3.256 × 10

__________

2.7 × 10

32.56

____

27

= 1.2059259259

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MR
Test #1 - Energetics
Assigned to Guests
by Trudy Jackson
Live Session
4 Questions

1
5
Calculate the standard enthalpy of formation of gaseous diborane (B2H6) using the following thermochemical information:
4B (s) + 3O2 (g)
→\rightarrow
→ 2B2O3 (s);
Δ\Delta
Δ H = -2509.1 kJ
2H2 (g) + O2 (g)
→\rightarrow
→ 2H2O (l);
Δ\Delta
Δ H = -571.7 kJ
B2H6 (g) + 3O2 (g)
→\rightarrow
→ B2O3 (s) + 3H2O (l);
Δ\Delta
Δ H = -2147.5 kJ
(click below to write/draw)

=

B2H6(G)

2B(S)+3H2
Show Your Work

2
5
Hydrogen cyanide can be prepared by the reaction:

CH4 (g) + NH3 (g)
→\rightarrow
→ HCN (g) + 3H2 (g)

What is the heat of reaction at constant pressure? Use the following thermochemical equations:

N2 (g) + 3H2 (g)
→ \rightarrow
→ 2NH3 (g);
Δ\Delta
Δ H = -91.8 kJ
C (graphite) + 2H2 (g)
→\rightarrow
→ CH4 (g);
Δ\Delta
Δ H = -74.9 kJ
H2 (g) + 2C (graphite) + N2 (g)
→\rightarrow
→2HCN (g);
Δ \Delta
Δ H = 270.3 kJ

(click below to write/draw)

3
5
Complete the following Born Haber cycle for barium phosphide, Ba3P2.
(click below to write/draw)

Show Your Work

4
5
Use bond energies to estimate
Δ\Delta
ΔH for the reaction below:
(click below to write/draw)

Show Your Work

You have responded to 1 of 4 questions.
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4


gesture
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Hydrogen cyanide can be prepared by the reaction:

CH4 (g) + NH3 (g)
→\rightarrow
→ HCN (g) + 3H2 (g)

What is the heat of reaction at constant pressure? Use the following thermochemical equations:

N2 (g) + 3H2 (g)
→ \rightarrow
→ 2NH3 (g);
Δ\Delta
Δ H = -91.8 kJ
C (graphite) + 2H2 (g)
→\rightarrow
→ CH4 (g);
Δ\Delta
Δ H = -74.9 kJ
H2 (g) + 2C (graphite) + N2 (g)
→\rightarrow
→2HCN (g);
Δ \Delta
Δ H = 270.3 kJ

Your sick puppy is diagnosed with roundworms. They grow inside of the puppy. What type of symbiotic relationship do the puppy and the roundworms have?

A. Cooperative
B. Commensalism
C. Mutualism
D. parasitism

30 N

60 N
20 N
Net force:
Resulting force:

What are facts about Cells

k2co3 major species present when dissolved in water

If a species is unable to adapt within a
changing environment what can happen to
that species?

What part of a chemical is represented by the letters

How many grams of water can be heated from 25°C to 70°C using 15,000 J?

What is the name of the following compound?
Al4C3
-Silver carbonate
-Aluminum carbide
-Aluminum carborhte
-Silver carbide

2. in Journey to the Center of the Earth, by Jules Verne, an adventurer travels through the
layers of Earth until he reaches the center. While it is not possible actually to travel through
all of the layers of Earth, in what order would the adventurer have traveled to reach the
center? Rearrange the layers into the correct order Place the outer layer at the top and the
innernost layer at the bottom
1 Crust
3 Outercore
2 Mantie
4 Inner Core

A car starts from rest. It takes 6.0 seconds for the car to accelerate to 5 m/s2 W. What is the final velocity?

How many atoms are there in 0.075 mol of Pb

The picture shows a diver constructing artificial reef in a shallow area of the ocean. artificial reef is intended to affect the ocean ecosystem by-
A. removing pollution from the water
B. Providing shelter for marine organisms
C. Causing sediment to erode into deeper waters
D. Preventing people from overfishing along the shore

Why does increasing temperature generally increase the rate of a chemical reaction?
A. It increases the amount of reactant
B. It decreases the size of the reactant particles.
C. It causes the particles of the reactants to move faster and collide more often.
D. It increases the space between reactant particles so they have more room to move apart

fill in the blank question














please help asap!!!!!!!!!!!!!!

balance the equation C2H5OH + 3O2 → CO2 + H2O

please help me on this question

help me with both number 8 and 9, I actually pressed commensalism for both of them, please be sure of your answer, first one to answer gets brainliest!​

How are the cells produced through mitosis and meiosis different?

Help!
Which of the following can scientists NOT interpret by examining fossils?
A. How earth's environment has changed overtime.
B. How plants and animals have changed overtime.
C. The age of certain layers of rocks. D. How the pull of gravity has changed.​

We have 548 grams of CaCl2. How many molecules of CaCl2 do we have? (The molar mass of CaCl2 is 110.98 g/mol)

Group of answer choices
2.97 x 10^24 molecules
3.66 x 10^28 molecules
9.1 x 10^22 molecules
4.37 x 10^22 molecules

Describe the behavior of water molecules during each stage of the water cycle.


Hurry pls this is due by the end of the class period so like 10 MINUTES HELP

A reaction yields 6.25 grams of a product. What is the percent yield if the theoretical yield is 18.8 grams?

To find the volume of a ring, the water displacement method was used.
What is the volume of the ring with correct significant figures?

What are prevailing winds?
A) winds found along the equator that vary in speed
B) winds that change seasonally and vary in speed
C) winds found at the poles at a consistent speed
D) winds that blow in the same direction at a consistent speed

heat flows naturally from objects that have higher energy to those with?

In a reaction vessel of 10.0 I, heat 9.00 g of water so that it partially decomposes. In the equilibrium mixture, 0.250 mol of water vapor is then still present. (a) Calculate the equilibrium constant K under the given conditions. (b) How is the equilibrium of the reaction affected by i. 1° reduction in volume ii. 2° increase in temperature?​

There is 321 grams of H2SO4, how many molecules is this?

Directions: Fill in the blanks with the correct terms to complete the statements. Write your answer on your answer
sheet.
1. Landforms like tall_______
act as an obstacle to traveling air masses, forcing them to rise over the peaks.

2.A___________is likely to dissolve or decrease its wind speed when it passes over a mountain or a mountain range.

3. Bodies of water like________is the main factor in the formation of typhoon.

4. The air in bodies of water is__________due to the evaporation of water.

5. Warm air builds up or increases the__________of a tropical cyclone.

help this question plzzss
I gave brainlest...​

How many milliliters are in 458 liters?