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3 years ago

Consider this reaction: KOH + HBr --> KBr + H2O

Chemistry

2 answers:

True [87]3 years ago

7 0

Answer:

B) It turns clear phenolphthalein pink.

Explanation:

KOH is a basic solution.

It turns red litmus paper turns blue.

It turns clear phenolphthalein pink.

The reagent which reacts with metals to form hydrogen gas is acid.

So, the right choice is:

B) It turns clear phenolphthalein pink.

Ymorist [56]3 years ago

5 0

Answer : the answer is B

Explanation: it turns clear phenolphthein pink

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A gas sample has a temperature of 22c with an unknown volume. The same gas has a volume of 456 mL when the temperature is 86c wi

Mkey [24]

The initial volume is 116.65 mL

Explanation:

Given:

Temperature, T₁ = 22°C

T₂ = 86°C

Volume, V₂ = 456 m

V₁ = ?

According to Charle's law:

$\frac{V_1}{T_1} = \frac{V_2}{T_2}$

Substituting the values:

$\frac{V_1}{22} =\frac{456}{86} \\\\V_1 = \frac{456 X 22}{86} \\\\V_1 = 116.65 mL$

Therefore, the initial volume is 116.65 mL

3 0

3 years ago

If 15.00 mL of 0.0100 M Ca(IO3)2 solution are mixed with 0.500 g KI, what is the theoretical yield (in grams) of I2?

n200080 [17]

The theoretical yield of I2 in the reaction would be 0.23 g

<h3>Theoretical yield</h3>

This refers to the stoichiometric yield of a reaction.

From the equation of the reaction:

Ca(IO3)2 + 10 KI + 12 HCl → 6 I2 + CaCl2 + 10 KCl + 6 H2O

The mole ratio of Ca(IO3)2 and I2 is 1: 6

Mole of 15.00 mL, 0.0100 M Ca(IO3)2 = 15/1000 x 0.0100

= 0.00015 mole

Equivalent mole of I2 = 0.00015 x 6

= 0.009 mole

mass of 0.0009 I2 = 0.0009 x 253.809

= 0.23 g

More on stoichiometric calculations can be found here: brainly.com/question/6907332

8 0

3 years ago

Part A

Roman55 [17]

These are two questions and two answers

Question 1.

Answer:

7.33 × 10 ⁻³ c

Explanation:

1) Data:

a) m = 9.11 × 10⁻³¹ kg

b) λ = 3.31 × 10⁻¹⁰ m

c) c = 3.00 10⁸ m/s

d) s = ?

2) Formula:

The wavelength (λ), the speed (s), and the mass (m) of the particles are reltated by the Einstein-Planck's equation:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

Solve for s:

s = h / (m.λ)

Substitute:

s = 6.626×10⁻³⁴J.s / ( 9.11 × 10⁻³¹ kg × 3.31 × 10⁻¹⁰ m) = 2.20 × 10 ⁶ m/s

To express the speed relative to the speed of light, divide by c = 3.00 10⁸ m/s

s = 2.20 × 10 ⁶ m/s / 3.00 10⁸ m/s = 7.33 × 10 ⁻³

Answer: s = 7.33 × 10 ⁻³ c

Question 2.

Answer:

2.06 × 10 ⁻³⁴ m.

Explanation:

1) Data:

a) m = 45.9 g (0.0459 kg)

b) s = 70.0 m/s

b) λ = ?

2) Formula:

Macroscopic matter follows the same Einstein-Planck's equation, but the wavelength is so small that cannot be detected:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

λ = h / (m.s)

Substitute:

λ = 6.626×10⁻³⁴J.s / ( 0.0459 kg × 70.0 m/s) = 2.06 × 10 ⁻³⁴ m

As you see, that is tiny number and explains why the wave nature of the golf ball is undetectable.

Answer: 2.06 × 10 ⁻³⁴ m.

5 0

3 years ago

If a sample containing 2.00 mL of nitroglycerin (density=1.592g/mL) is detonated, how many total moles of gas are produced?

fgiga [73]

The overall balanced chemical reaction for this is:

Detonation of Nirtoglycerin 
4 C3H5N3O9 --> 12 CO2 + 6 N2 + O2 + 10 H2O

Therefore:

2.00 mL x 1.592 g/mL = 3.184 g 
3.184 g / 227.1 /mol = 0.0140 mol nitroglycerin
4 moles --> 12 + 6 + 1 + 10 = 29 moles of gas
0.0140 mol x (29/4) = 0.1017 moles of gases or (0.102 mol)

6 0

3 years ago

What us energy stored in an object called

Vikentia [17]

Answer:

potential energy

Explanation:

4 0

3 years ago

Read 2 more answers