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3 years ago

7

A train is accelerating at a rate of 2 m/s squared. if its initial speed of 20 m/s how long does it take the train to reach a sp

eed of 80 m/s

1 answer:

marusya05 [52]3 years ago

5 0

Answer:

30s

Explanation:

Set up the equation and solve for x:

2x+20=80

2x=60

x=30

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Hydrogen iodide, HI, is formed in an equilibrium reaction when gaseous hydrogen and iodine gas are heated together. If 20.0 g of

Kaylis [27]

Answer: D. 19.9 g hydrogen remains.

Explanation:

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

a) moles of $H_2$

$\text{Number of moles}=\frac{20.0g}{2g/mol}=10.0moles$

b) moles of $I_2$

$\text{Number of moles}=\frac{20.0g}{254g/mol}=0.0787moles$

$H_2(g)+I_2(g)\rightarrow 2HI(g)$

According to stoichiometry :

1 mole of $I_2$ require 1 mole of $H_2$

Thus 0.0787 moles of $l_2$ require= $\frac{1}{1}\times 0.0787=0.0787moles$ of $H_2$

Thus $l_2$ is the limiting reagent as it limits the formation of product and $H_2$ acts as the excess reagent. (10.0-0.0787)= 9.92 moles of $H_2$ are left unreacted.

Mass of $H_2=moles\times {\text {Molar mass}}=9.92moles\times 2.01g/mol=19.9g$

Thus 19.9 g of $H_2$ remains unreacted.

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3 years ago

How many grams of oxygen gas (02) are needed to completely react with 9.30 moles

Luba_88 [7]

Answer:

223 g O₂

Explanation:

To find the mass of oxygen gas needed, you need to (1) convert moles Al to moles O₂ (via the mole-to-mole ratio from reaction coefficients) and then (2) convert moles O₂ to grams O₂ (via the molar mass). When writing your ratios/conversions, the desired unit should be in the numerator in order to allow for the cancellation of the previous unit. The final answer should have 3 sig figs because the given value (9.30 moles) has 3 sig figs.

4 Al + 3 O₂ ----> 2 Al₂O₃
^ ^

Molar Mass (O₂): 32.0 g/mol

9.3 moles Al 3 moles O₂ 32.0 g
------------------- x --------------------- x -------------------- = 223 g O₂
4 moles Al 1 mole

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2 years ago

What is science? Why do you think science is important?

ryzh [129]

Answer:

Science is the study of the physical or material world. Science is important because it can answer questions about new ideas and can advance technologies

Explanation:

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3 years ago

If a 58 g sample of metal at 100 c is placed into calorimeter containing 60g of water at 18 c , the temperature of the water inc

tatiyna

Answer:

The water will absorb 1004.16 Joule of heat

Explanation:

Step 1: Data given

Mass of the metal = 58.00 grams

Temperature of the metal = 100.00 °C

Mass of water = 60.00 grams

Temperature of water = 18.00 °C

Final temperature = 22.00 °C

Specific heat of water = 4.184 J/g°C

Step 2: Calculate the amount of heat absorbed by the water in joules

Q = mass *specific heat *ΔT

⇒ with Q = the heat absorbed by water

⇒ with mass of water = 60.00 grams

⇒ with specific heat of water = 4.184 J/g°C

⇒ with ΔT = The change in temperature of water = T2 - T1 = 22 - 18 = 4.0 °C

Q = 60.00 * 4.184 J/g°C * 4.0 °C

Q = 1004.16 J

The water will absorb 1004.16 Joule of heat

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3 years ago

As the temperature of a substance decreases, the

77julia77 [94]

Remains the same because temperature can't change energy

7 0

3 years ago

Read 2 more answers