1. What would the pOH of a solution that causes the cyanidin indicator to turn purple be?

tresset_1 [31]

Answer:

Explanation:

1) During the diagnosis of thyroid disease a 10 g sample of I-131 is used. After a period of 32 days, how much sample is still radio active.?

Answer:

0.625 g

Explanation:

HL = Elapsed time/half life

32 days/8 days = 4

At time zero = 10 g

At 1st half life = 10/2 = 5 g

At 2nd half life = 5/2 = 2.5 g

At 3rd half life = 2.5 /2 = 1.25 g

At 4th half life = 1.25 / 2 = 0.625 g

After 32 days still 0.625 g of I-131 remain radioactive.

2) what was the original mass of sample Tc-99 that was used to locate the brain tumor If 0.10 g of a sample remains after 30 days? (half life 6 days)

Answer:

0.32 g.

Explanation:

Half life = time elapsed / HL

Half life = 30 days / 6 days = 5

At 5th half life = 0.10 g

At 4th half life = 0.2 g

At 3rd half life = 0.4 g

At 2nd half life = 0.8 g

At 1st half life = 0.16 g

At time zero = 0.32 g

The original amount was 0.32 g.

3) write the beta decay equation of I-131?

Equation:

¹³¹I₅₃ → ¹³¹Xe₅₄ + ⁰₋₁e

Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.

The mass of beta particle is smaller than the alpha particles.

They can travel in air in few meter distance.

These radiations can penetrate into the human skin.

The sheet of aluminium is used to block the beta radiation

¹³¹I₅₃ → ¹³¹Xe₅₄ + ⁰₋₁e

The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.

3 0

3 years ago

Why does an incomplete combustion reaction occur?

Natasha_Volkova [10]

Incomplete combustion occurs when the supply of air or oxygen is poor. Water is still produced, but carbon monoxide and carbon are produced instead of carbon dioxide. ... Carbon monoxide is a poisonous gas, which is one reason why complete combustion is preferred to incomplete combustion.

8 0

3 years ago

Which statement correctly describes the differences between positive and negative acceleration?

aliya0001 [1]

Answer:

POSITIVE DESCRIBES AN INCREASE IN SPEED AND NEGATIVE DESCRIBES A DECREASE IN SPEED.

Explanation:

7 0

3 years ago

A student finds two unlabeled flasks of clear liquids. One is believed to be 0.1 m nacl and the other to be 0.1 m naclo3. What i

KonstantinChe [14]

Answer:

Add AgNO₃ solution to both unlabeled flasks: based on solubility rules, you can predict that when you add AgNO₃ to the NaCl solution, you will obtain AgCl precipitate, while no precipitate will be formed from the NaClO₃ solution.

Explanation:

1. Adding AgNO₃ to NaCl solution:

AgNO₃ (aq) + NaCl (aq) → AgCl (s) + NaNO₃ (aq)

2. Adding AgNO₃ to NaClO₃ solution

AgNO₃ (aq) + NaClO₃ (aq) → AgClO₃ (aq) + NaNO₃ (aq)

3. Relevant solubility rules for the problem.

Although most salts containing Cl⁻ are soluble, AgCl is a remarkable exception and is insoluble.

All chlorates are soluble, so AgClO₃ is soluble.

Salts containing nitrate ion (NO₃⁻) are generally soluble and NaNO₃ is not an exception to this rule. In fact, NaNO₃ is very well known to be soluble.

Hence, when you add AgNO₃ to the NaCl solution the AgCl formed will precipitate, and when you add the same salt (AgNO₃) to the AgClO₃ solution both formed salts AgClO₃ and NaNO₃ are soluble.

Then, the precipiate will permit to conclude which flask contains AgCl.

6 0

3 years ago

What mass of water is produced from the complete combustion of 7.10×10−3 g of methane? Express your answer with the appropriate

Ann [662]

Answer:

16 mg of water can be produced by 7.1×10⁻³ g of CH₄

Explanation:

This is the reaction:

CH₄ + 2O₂ → CO₂ + 2H₂O

In a combustion, oxgen is a reactant with another compound, and the products are always water and carbon dioxide

1 mol of methane can produce 2 moles of water. Ratio is 1:2

If we convert the mass to moles → 7.1×10⁻³ g . 1 mol/ 16g = 4.43×10⁻⁴ mol

In this reaction I would produce the double of moles I have from methane, so If I have 4.43×10⁻⁴ moles of methane I would produce 8.87×10⁻⁴ moles of water.

What mass of water, corresponds to 8.87×10⁻⁴ moles?

8.87×10⁻⁴ mol . 18g / 1mol = 0.016 g which is actually the same as 16 mg

6 0

4 years ago