Find the volume of a cereal box that has the dimensions of 35.2 cm x 220 cm x 6.0 cm

What element produces violet light of approximately 412 nm?

Natali [406]

a. Hydrogen

Hydrogen has a line at 410 nm.
Mercury has a line at 405 nm.
Sodium and neon have no lines near 412 nm.

8 0

2 years ago

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If the ionization constant of water, kw, at 40°c is 2.92 × 10-14, then what is the hydronium ion concentration and ph for an aci

charle [14.2K]

Answer is: the hydronium ion concentratio is 1.71×10⁻⁷ mol/dm³ and pH<6.76.

The Kw (the ionization constant of water) at 40°C is 2.94×10⁻¹⁴ mol²/dm⁶ or 2.94×10⁻¹⁴ M².

Kw = [H₃O⁺] · [OH⁻].

[H₃O⁺] = [OH⁻] = x.

Kw = x².

x = √Kw.

x = √2.94×10⁻¹⁴ M².

x = [H₃O⁺] = 1.71×10⁻⁷ M; concentration of hydronium ion.

pH = -log[H₃O⁺].

pH = -log(1.71×10⁻⁷ M).

pH = 6.76.

pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.

5 0

2 years ago

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Define the following: Bronsted-Lowry acid - Lewis acid- Strong acid - (5 points) Problem 6: Consider the following acid base rea

Allushta [10]

Answer: Yes, $HCl$ is a strong acid.

acid = $HCl$ , conjugate base = $Cl^-$ , base = $H_2O$ , conjugate acid = $H_3O^+$

Explanation:

According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

Yes $HCl$ is a strong acid as it completely dissociates in water to give $H^+$ ions.

$HCl\rightarrow H^++Cl^-$

For the given chemical equation:

$HCl+H_2O\rightarrow H_3O^-+Cl^-$

Here, $HCl$ is loosing a proton, thus it is considered as an acid and after losing a proton, it forms $Cl^-$ which is a conjugate base.

And, $H_2O$ is gaining a proton, thus it is considered as a base and after gaining a proton, it forms $H_3O^+$ which is a conjugate acid.

Thus acid = $HCl$

conjugate base = $Cl^-$

base = $H_2O$

conjugate acid = $H_3O^+$ .

8 0

2 years ago

Balance this equation. If a coefficient of "1" is required, choose "blank" for that box. C2H6 + O2 → CO2 + H2O

fenix001 [56]

Step 1: Write the unbalanced equation,

C₂H₆  + O₂   → CO₂  + H₂<span>O

There are 2 C at left hand side and 1 carbon at right hand side. So, multiply CO</span>₂ by 2 to balance C atoms at both side. So,

C₂H₆  + O₂   → 2 CO₂  + H₂O

Now, count number of H atoms at both sides. There are 6 H atoms at left hand side and 2 at right hand side. Multiply H₂O by 3 to balance H atoms.

C₂H₆  + O₂   → 2 CO₂  + 3 H₂O

At last, balance O atoms. There are 2 O atoms at left hand side and 3 O atoms at right hand side. Multiply O₂ with 1.5 (i.e. 3/2) to balance O atoms. i.e.

C₂H₆  + 3/2 O₂   → 2 CO₂  +  3 H₂O

Hence, the equation is balanced. If you want to make equation fraction free then multiply all equation with 2. i.e.

( C₂H₆  + 3/2 O₂   → 2 CO₂  +  3 H₂O ) × 2

2 C₂H₆  + 3 O₂   → 4 CO₂  +  6 H₂O

5 0

2 years ago

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70 points and will give brainliest

ikadub [295]

Answer:

74mL

Explanation:

Given parameters:

Molar mass of citric acid = 192g/mol

Molar mass of baking soda = 84g/mol

Concentration of citric acid = 0.8M

Mass of baking powder = 15g

Unknown parameters:

Volume of citric acid = ?

Solution

Equation of the reaction:

C₆H₈O₇ + 3NaHCO₃ → Na₃C₆H₅O₇ + 3H₂O + 3CO₂

Procedure:

We work from the known parameters to the unknown. From the statement of the problem, we can approach the solution from the parameters of the baking powder.
From the baking powder, we can establish a molar relationship between the two reactants. We employ the mole concept in this regard.
We find the number of moles of the baking powder that went into the reaction using the expression below:

Number of moles = $\frac{mass}{molar mass}$