What metallic element is sometimes used in flares because it burns bright?

Fill in the coefficients that will balance the following reaction: a0Ca + a1CO2 + a2O2 → a3CaCO3

VashaNatasha [74]

The chemical equation without coefficients is:

Ca + CO2 + O2 --------> Ca CO3

You can balance that equation by trial an error.

This is the chemical equation balanced:

2Ca + 2CO2 + O2 --------> 2Ca CO3

Count the atoms on each side to check the balance

Atom Left side    right side

Ca    2    2

C    2    2

O 2*2 + 2 = 6    2*3 = 6

Then those are the coefficients:

a0 = 2

a1 = 2

a2 = 1

a3 = 2

6 0

4 years ago

Giving 30 points!! please help <3

TiliK225 [7]

Answer:

below :)

Explanation:

Bones, droppings, and other dead matter

Energy storage molecules, cellular respiration

Process, energy

Oxygen, energy storage molecules, energy, carbon dioxide

Cellular respiration, carbon

Carbon, nitrogen

Nitrogen

Decomposers, ecosystem

3 0

2 years ago

A student dissolved 1.805g of a monoacidic weak base in 55mL of water. Calculate the equilibrium pH for the weak monoacidic base

yawa3891 [41]

Answer:

11.39

Explanation:

Given that:

$pK_{b}=4.82$

$K_{b}=10^{-4.82}=1.5136\times 10^{-5}$

Given that:

Mass = 1.805 g

Molar mass = 82.0343 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{1.805\ g}{82.0343\ g/mol}$

$Moles= 0.022\ moles$

Given Volume = 55 mL = 0.055 L ( 1 mL = 0.001 L)

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

$Molarity=\frac{0.022}{0.055}$

Concentration = 0.4 M

Consider the ICE take for the dissociation of the base as:

B + H₂O ⇄ BH⁺ + OH⁻

At t=0 0.4 - -

At t =equilibrium (0.4-x) x x

The expression for dissociation constant is:

$K_{b}=\frac {\left [ BH^{+} \right ]\left [ {OH}^- \right ]}{[B]}$

$1.5136\times 10^{-5}=\frac {x^2}{0.4-x}$

x is very small, so (0.4 - x) ≅ 0.4

Solving for x, we get:

x = 2.4606×10⁻³ M

pOH = -log[OH⁻] = -log(2.4606×10⁻³) = 2.61

5 0

3 years ago

100 ml of a 0.300 m solution of agno3 reacts with 100 ml of a 0.300 m solution of hcl in a coffee-cup calorimeter and the temper

Olin [163]

Answer:

100 ml of a 0.300 m solution of agno3 reacts with 100 ml of a 0.300 m solution of hcl in a coffee-cup calorimeter and the temperature rises from 21.80 °c to 23.20 °c. Assuming the density and specific heat of the resulting solution is 1.00 g/ml and 4.18 j/g ∙ °c respectfully, what is the ΔH°rxn?

39.013 kJ/mol.

Explanation:

AgNO3(aq) + HCl(aq) --------------> AgCl(s) + HNO3(aq)

We can calculate the amount of heat (Q) released from the solution using the relation:

Q = m.c.ΔT,

Where, Q is the amount of heat released from the solution (Q = ??? J).

m is the mass of the solution (m of the solution = density of the solution x volume of the solution = (1.0 g/mL)(200 mL) = 200 g.

c is the specific heat capacity of the solution (c = 4.18 J/g∙°C).

ΔT is the difference in the T (ΔT = final temperature - initial temperature = 23.20 °C - 21.80 °C = 1.4 °C).

∴ Q = m.c.ΔT = (200 g)(4.18 J/g∙°C)(1.4 °C) = 1170.4 J.

∵ ΔH°rxn = Qrxn/(no. of moles of AgNO₃).

Molarity (M) is defined as the no. of moles of solute dissolved in a 1.0 L of the solution.

M = (no. of moles of AgNO₃)/(Volume of the solution (L)).

∴ no. of moles of AgNO₃

= (M)(Volume of the solution (L))

= (0.3 M)(0.1 L) = 0.03 mol.

∴ ΔH°rxn

= Qrxn/(no. of moles of AgNO₃)

= (1170.4 J)/(0.03 mol)

= 39013.33 J/mol

= 39.013 kJ/mol.

7 0

3 years ago

What is the Brønsted-Lowry base in this reaction: NH2−+CH3OH→NH3+CH3O−?(1 point)CH3O−cap c cap h sub 3 cap o raised to the negat

Fynjy0 [20]

In the reaction as follows: NH2- + CH3OH → NH3 + CH3O−, NH2- is the Brønsted-Lowry base.

BRØNSTED-LOWRY BASE:

According to Bronsted-Lowry definition of a base and acid, a base is substance that accepts an hydrogen ion or proton (H+) while an acid is a substance that donates a proton.

According to this reaction given as follows: NH2 + CH3OH → NH3+ CH3O-

NH2- is a reactant that accepts a hydrogen ion (H+) to become NH3+
NH3+CH3OH is a reactant that donates hydrogen ion (H+)

Since NH2- accepts a proton, this means that in the reaction as follows: NH2 + CH3OH → NH3 + CH3O−, NH2- is the Brønsted-Lowry base.

Learn more at: brainly.com/question/21736327?referrer=searchResults

3 0

3 years ago