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3 years ago

PLEASE HELP MEEEE

Chemistry

2 answers:

Sholpan [36]3 years ago

4 0

Answer:

spf 30

Explanation:

its a good sunscreen btw

Anna35 [415]3 years ago

4 0

SPF 15 or higher used daily

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Nitrogen dioxide is used industrially to produce nitric acid, but it contributes to acid rain and photochemical smog. What volum

Gnom [1K]

The reaction of nitric acid with copper is:

Cu(s) + 4HNO₃ → Cu(NO₃)₂ + 2NO₂(g) + 2H₂O(l)

Moles of copper are: 4.95cm3 X8.95gmX1mol / 63.55gmX1mol

=0.697moles

Moles of nitric acid are: 230mlX 1.42gm X68gmX1mol / 63.01gmX100gm

=3.52moles

As 1 mol of Cu reacts with 4 moles of HNO₃

=0.697 mol Cu × (4mol HNO₃ / 1mol Cu) = 2.79 moles of HNO₃ will react. That means Cu is limiting reactant.

Moles of NO₂ produced are:

0.697 mol Cu × (2mol NO₂ / 1mol Cu) = 1.394 moles of NO₂

Using PV = nRT

Where P is pressure (735torr / 760 = 0.967atm) ; n are moles (1.394mol);

R is gas constant (0.082atmL/molK); T is temperature (28.2°C + 273.15 = 301.35K).

Thus, volume is:V = nRT / P

V = 1.394mol×0.082atmL/molK×301.35K / 0.967atm

V = 35.6L

The volume of nitrogen oxide formed is 35.6L

To know more about nitrogen dioxide here

brainly.com/question/15682963

#SPJ4

4 0

2 years ago

3.9 X 1022 molecules of CO2 = _ moles of CO2

agasfer [191]

Answer:

moles CO2 = 0.065 moles

Explanation:

mole = 6.022 E23 molecules.....Avogadro

∴ molecules CO2 = 3.9 E22 molecules

⇒ moles CO2 = (3.9 E22 molecules CO2)×( moles CO2/ 6.022 E23 molecules CO2)

⇒ moles CO2 = 0.065 moles

7 0

3 years ago

Consider the general reversible reaction. Lower A upper A plus lower B upper B double-headed arrow lower C upper C plus Lower d

dimulka [17.4K]

Answer: K e q equals StartFraction StartBracket upper C EndBracket superscript lower c StartBracket upper D EndBracket superscript lower D over StartBracket upper A EndBracket superscript lower a StartBracket upper B EndBracket superscript lower b EndFraction.

Explanation:

Equilibrium constant is the ratio of the concentration of products to the concentration of reactants each term raised to its stochiometric coefficients. It is represented by the symbol $K_{eq}$

The balanced chemical reaction is:

$aA+bB\rightleftharpoons cC+dD$

The expression for $K_{eq}$ is written as:

$K_{eq}=\frac{[C]^c\times [D]^d}{[A]^a\times [B]^b}$

Thus the correct option is K e q equals StartFraction StartBracket upper C EndBracket superscript lower c StartBracket upper D EndBracket superscript lower D over StartBracket upper A EndBracket superscript lower a StartBracket upper B EndBracket superscript lower b EndFraction.

3 0

3 years ago

The ph of a fruit juice is 3.2. find the hydronium ion concentration, left bracket upper h 3 upper o superscript plus right bra

melomori [17]

pH is referred to as the scale to describe the hydronium ion concentration of a

solution. It is used to measure the acidity or basicity of a solution. pH of an acidic solution is less than 7, a neutral solution is 7, and a basic solution is greater than 7.

pH can be calculated using the formula:

$pH = - log [H_{3}O^{+}]$

Given the pH of solution is 3.2.

Finding out the concentration of hydronium ion from pH.

$pH = - log[H_{3}O^{+}]$

$3.2 = - log [H_{3}O^{+}]$

$[H_{3}O^{+}] = 10^{-3.2}$

$[H_{3}O^{+}] = 6.3 * 10^{-4} M$

Therefore, the hydronium ion concetration of the solution is $6.3 * 10^{-4} M$

3 0

3 years ago

Name an element or elements in the periodic table that you would expect to be chemically similar to potassium. check all that ap

Inga [223]

It would have to be all elements in the same family, so since potassium is an Alkali Metal the similar chemicals would be...Lithium, Sodium, Rubidium, Cesium, Francium.

7 0

3 years ago