Which of the following changes is observed when we move across the row from left to right in the periodic table?

At a festival, spherical balloons with a radius of 170.cm are to be inflated with hot air and released. The air at the festival

MissTica

Answer:

The correct answer is 1.5 balloons.

Explanation:

Based on the given question, the radius of the spherical balloons is 170 cm. Therefore, the volume of each balloon will be,

= 4/3 × π × (170)³ cm³

= 20.5176 × 10⁶ cm³

= 20.5176 m³

The density of air at 100 degree C s 0.946 Kg m⁻³

The mass of air in each balloon can be calculated by using the formula,

Mass = density × volume

Mass = 0.946 Kg m⁻³ × 20.5176 m³

Mass = 19.410 Kg

The heat energy, that is, required to bring the air from 25 degree C to 100 degree C will be,

= 19.410 × 10³ g × (100 -25) degree C × 1.009 J/g degree C

= 14.68 × 10⁵ J

The concentration of butane given is 1.00 Kg or 1000 g

The molecular weight of butane is 58.12 g per mole

The moles or n can be calculated by using the formula,

n = mass / mol.wt

n = 1000 g/58.12 g/mol = 17.20 mol

The formation of enthalpy of butane at 25 degree C is 125.7 × 10³ J/mol. The evolution of heat energy that take place at the time of burning 17.20 moles of butane is,

= 125.7 × 10³ J/mol × 17.20 mol

= 2.16 × 10⁶ J

The number of balloons that can be inflated with hot air is,

= 2.16 × 10⁶ J / 14.68 × 10⁵ J per each balloon

= 1.5 balloons

Hence, maximum of 1.5 balloons can be inflated.

7 0

4 years ago

(a) Write the dissolution reaction for solid Na2CO3 below. (Use the lowest possible coefficients. Include states-of-matter under

Andreas93 [3]

Answer:

For a: The chemical equation for the dissolution of sodium carbonate is $Na_2CO_3(s)\rightarrow Na_2CO_3(aq.)$

For b: The net acid-base reaction is $CO_3^{2-}(aq.)+H_2O(l)\rightarrow OH^-(aq.)+HCO_3^-(aq.)$

Explanation:

For a:

Dissolution reaction is defined as the reaction in which a solid compound gets dissolved in water to form aqueous solution.

The chemical equation for the dissolution of sodium carbonate follows:

$Na_2CO_3(s)\rightarrow Na_2CO_3(aq.)$

Ionization reaction is defined as the reaction in which an ionic compound dissociates into its ions when dissolved in aqueous solution.

The chemical equation for the ionization of sodium carbonate follows:

$Na_2CO_3(aq.)\rightarrow 2Na^+(aq.)+CO_3^{3-}(aq.)$

For b:

Now, the anion formed which is $CO_3^{2-}$ reacts with water to form conjugate acid.

The chemical equation for the reaction of anion with water follows:

$CO_3^{2-}(aq.)+H_2O(l)\rightarrow OH^-(aq.)+HCO_3^-(aq.)$

Hence, the net acid-base reaction of the anion formed and water is written above.

3 0

3 years ago

A sealed reaction vessel initially contains 1.113×10-2 moles of water vapor and 1.490×10-2 moles of CO(g).

Molodets [167]

Answer:

Kc = $\frac{[8.326x10-3]^{1} }{[1.113x10-2]^{1}[1.490x10-2]^{1} }$

Kc = 50.2059

Explanation:

1. Balance the equation

2. Use the Kc formula

Remember that pure substances, like H2 are not included on the Kc formula

4 0

3 years ago

Hypochlorous acid decays in the presence of ultraviolet radiation. Assume that degradation occurs accord- ing to first-order kin

Dennis_Churaev [7]

Answer:

35.75 days

Explanation:

From the given information:

For first-order kinetics, the rate law can be expressed as:

$\mathsf{In \dfrac{C}{C_o} = -kt}$

Given that:

the rate degradation constant = 0.12 / day

current concentration C = 0.05 mg/L

initial concentration C₀ = 3.65 mg/L

$\mathsf{In( \dfrac{0.05}{3.65})= -(0.12) t}$

㏑(0.01369863014) = -(0.12) t

-4.29 = -(0.12)

t = -4.29/-0.12

t = 35.75 days

3 0

3 years ago

Is a 93.3% solution dilute or concentrated? Dilute Concentrated

oksano4ka [1.4K]

Answer:

Concentrated

Explanation:

Concentration measures the amount of solute in a solution. There are many expressions of concentration. Some of then are percentage (mass/mass, volume/mass, volume/volume), molarity, molality, mole fraction, among others.

When a solution has a high concentration it is said that it is concentrated; when a solution has a low concentration is is said that is is diluted.

Concentrated solutions expressed in percentage typically have about 80 - 90% (or more) of solute.

Diluted solutions expressed in percentage, tipylcally have about 10% - 20% or less.

But they are not fixed limits. You might say that a 85% solution is concentrated. Acids at 75 % sure are concentrated.

Hence, a 93.3% solution is concentrated, definitely.

3 0

3 years ago