2B + 3H2 2BH3 How many moles of BH3 are synthesized when 27.0 moles of H2 completely react?

The concept of empiricism states that all rationally accepted knowledge is determined from experience. Francis bacon was one of

lawyer [7]

the answer is option D "people emphasized obtaining knowledge through scientific experiments" (on plato)

6 0

2 years ago

Which electron transition represents a gain of energy?

xz_007 [3.2K]

The correct answer is (A) from 2nd to 3rd shell.

The explanation :

when a gain of energy is the shift of the electrons from a shell of low energy to the shell of high energy

and we have here 2nd shell is the shell of low energy, and 3rd shell is the shell of high energy.

∴ (A) from 2nd to 3rd shell is the correct answer.

5 0

3 years ago

A 44.0 g sample of an unknown metal at 99.0 oC was placed in a constant-pressure calorimeter of negligible heat capacity contain

tatiyna

Answer:

$C_m=0.474\frac{J}{g\°C}$

Explanation:

Hello.

In this case, since this is a system in which the water is heated up and the metal is cooled down in a calorimeter which is not affected by the heat lose-gain process, we can infer that the heat lost by the metal is gained be water, it means that we can write:

$Q_m=-Q_w$

Thus, in terms of masses, specific heats and temperatures we can write:

$m_mC_m(T_{eq}-T_m)=-m_wC_w(T_{eq}-T_w)$

Whereas the equilibrium temperature is the given final temperature of 28.4 °C and we can compute the specific heat of the metal as shown below:

$C_m=\frac{-m_wC_w(T_{eq}-T_w)}{m_m(T_{eq}-T_m)}$

Plugging the values in and since the density of water is 1.00 g/mL so the mass is 80.0g, we obtain:

$C_m=\frac{-80.0g*4.184\frac{J}{g\°C} (28.4\°C-24.0\°C)}{44.0g(28.4\°C-99.0\°C)}\\\\C_m=0.474\frac{J}{g\°C}$

Best regards!

6 0

2 years ago

H2S what species are present at 10-6 mol/L or greater when dissolved in water

Anastaziya [24]

Answer:

the answer has been given below have a good day

Explanation:

mark as brainiest

5 0

2 years ago

What is the density of motor oil in g/mL if 1.25 quart (qt) weighs 2.25 pounds (lb)?

Doss [256]

Answer:

0.86 g/mL

Explanation:

In order to solve the problem, you have to know the formula for "Density." Density refers to "mass per unit volume." It's formula is:

Density (ρ) = $\frac{mass}{Volume}$

Next, we have to convert the units of measurement in accordance to what is being asked in the problem. It is asking for "g/mL," which means we have to convert 1.25 quarts (qt.) to mL and 2.25 pounds (lbs.) to grams.

Let's solve.