Which group iia metal magnesium or calcium is more active cite your evidence?

A chemical indicator that changes colors depending on the concentration of h+ in the solution is called a

DanielleElmas [232]

Answer is: acid-base indicator or pH indicators.

Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄). Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Another example is methyl orange. It is red colour in acidic solutions and yellow colour in basic solutions.

3 0

3 years ago

How much energy is needed to raise the temperature of 125g of water from 25.0oC to 35.0oC? The specific heat of water is 4.184

Anvisha [2.4K]

Hello!

To find the amount of energy need to raise the temperature of 125 grams of water from 25.0° C to 35.0° C, we will need to use the formula: q = mcΔt.

In this formula, q is the heat absorbed, m is the mass, c is the specific heat, and Δt is the change in temperature, which is found by final temperature minus the initial temperature.

Firstly, we can find the change in temperature. We are given the initial temperature, which is 25.0° C and the final temperature, which is 35.0° C. It is found by subtract the final temperature from the initial temperature.

35.0° C - 25.0° C = 10.0° C

We are also given the specific heat and the grams of water. With that, we can substitute the given values into the equation and multiply.

q = 125 g × 4.184 J/g °C × 10.0° C

q = 523 J/°C × 10.0° C

q = 5230 J

Therefore, it will take 5230 joules (J) to raise the temperature of the water.

6 0

3 years ago

How do I solve the following word problem: The half-life of Phosphorus - 32 is 14.3 days. It is used to study a plant's use of f

BaLLatris [955]

Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.

We have the following equation representing the half-life decay:

$A=A_o\times2^{(-\frac{t}{t_{half}})_{}_{}}$

A is the resulting amount after t time

Ao is the initial amount = 50 mg

t= Elapsed time

t half is the half-life of the substance = 14.3 days

We replace the know values into the equation to have an exponential decay function for a 50mg sample

$A=\text{ 50 }\times2^{\frac{-t}{14.3}}$

That would be the answer for a)

To know the P-32 remaining after 84 days we have to replace this value in the equation:

$\begin{gathered} A=\text{ 50 }\times2^{\frac{-84}{14.3}} \\ A=0.85\text{ mg} \end{gathered}$

So, after 84 days the P-32 remaining will be 0.85 mg

4 0

1 year ago

Do sec-butyl alcohol has two stereoisomers.

denis23 [38]

Answer:

yes

Explanation:

3 0

2 years ago

If the initial temperature of a movable cylinder was 50 degrees Celsius

slega [8]

Answer:

8.45 L

Explanation:

From the question given above, the following data were obtained:

Initial temperature (T₁) = 50 °C

Initial pressure (P₁) = 2 atm

Initial volume (V₁) = 5 L

Final temperature (T₂) = 0 °C

Final pressure (P₂) = 1 atm

Final volume (V₂) =?

Next, we shall convert celsius temperature to Kelvin temperature. This can be obtained as follow:

T(K) = T(°C) + 273

Initial temperature (T₁) = 50 °C

Initial temperature (T₁) = 50 °C + 273

Initial temperature (T₁) = 323 K

Final temperature (T₂) = 0 °C

Final temperature (T₂) = 0 °C + 273

Final temperature (T₂) = 273 K

Finally, we shall determine the new volume. This can be obtained as follow:

Initial temperature (T₁) = 323 K

Initial pressure (P₁) = 2 atm

Initial volume (V₁) = 5 L

Final temperature (T₂) = 273 k

Final pressure (P₂) = 1 atm

Final volume (V₂) =?

P₁V₁ / T₁ = P₂V₂ / T₂

2 × 5 / 323 = 1 × V₂ / 273

10 / 323 = V₂ / 273

Cross multiply

323 × V₂ = 10 × 273

323 × V₂ = 2730

Divide both side by 323

V₂ = 2730 / 323

V₂ = 8.45 L

Thus, the new volume is 8.45 L

5 0

3 years ago