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garri49 [273]
3 years ago
7

Can you answer both questions please??

Chemistry
1 answer:
zhenek [66]3 years ago
3 0
The air we breathe is a mixture and for number 10th they are elements.
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Human blood typically contains 1.04 kg/L of platelets. A 1.89 pints of blood would contain what mass (in grams) of platelets
Fynjy0 [20]

Answer:

The correct answer is 930 grams platelets.

Explanation:

The volume of blood given is 1.89 pints. Total number of gallons in 1.89 pints is,  

= 1.89/8 = 0.236 gallon

1 gallon comprise = 3.785 L

So, 0.236 gallon comprise = 0.236 * 3.785 L = 0.89 L

As mentioned that 1 Liter of blood comprise 1.04 kilograms of platelets. Therefore, 0.89 L of blood will contain = 1.04 * 0.89 = 0.93 Kg platelets

1 Kg contain 1000 grams. So, number of platelets in grams will be,  

= 1000 * 0.93 = 930 grams platelets.  

3 0
3 years ago
ethanol is a common laboratory solvent and has a density of 0.789 g/mL. what is the mass, in grams, of 151 mL of ethanol
natta225 [31]
<em>V = 151 mL = 151 cm³</em>
<em>d = 0,789 g/mL = 0,789 g/cm³</em>
--------------------------------------

d = m/V
m = d×V
m = 0,789×151
<u>m = 119,139g</u>

3 0
3 years ago
Read 2 more answers
The least active elements are the _______.
Andreas93 [3]
Noble gases are the least<span> reactive </span>elements<span> in the periodic table because they have a full valence shell. Examples are, Argon, Neon, Xenon, and Helium</span>
4 0
3 years ago
Ne, c4h10, is a component of natural gas that is used as fuel for cigarette lighters. the balanced equation of the complete comb
Simora [160]
<span>3.68 liters First, determine the number of moles of butane you have. Start with the atomic weights of the involved elements: Atomic weight carbon = 12.0107 Atomic weight hydrogen = 1.00794 Atomic weight oxygen = 15.999 Molar mass butane = 4*12.0107 + 10*1.00794 = 58.1222 g/mol Moles butane = 2.20 g / 58.1222 g/mol = 0.037851286 Looking at the balanced equation for the reaction which is 2 C4H10(g)+13 O2(g)→8 CO2(g)+10 H2O(l) It indicates that for every 2 moles of butane used, 8 moles of carbon dioxide is produced. Simplified, for each mole of butane, 4 moles of CO2 are produced. So let's calculate how many moles of CO2 we have: 0.037851286 mol * 4 = 0.151405143 mol The ideal gas law is PV = nRT where P = Pressure V = Volume n = number of moles R = Ideal gas constant ( 0.082057338 L*atm/(K*mol) ) T = absolute temperature (23C + 273.15K = 296.15K) So let's solve the formula for V and the calculate using known values: PV = nRT V = nRT/P V = (0.151405143 mol) (0.082057338 L*atm/(K*mol))(296.15K)/(1 atm) V = (3.679338871 L*atm)/(1 atm) V = 3.679338871 L So the volume of CO2 produced will occupy 3.68 liters.</span>
4 0
3 years ago
6. An environmental chemist needs a carbonate buffer of pH 10.00 to study the effects of acid rain on limestone-rich soils. To p
pishuonlain [190]

Answer:

[Na₂CO₃] = 0.094M

Explanation:

Based on the reaction:

HCO₃⁻(aq) + H₂O(l) ↔ CO₃²⁻(aq) + H₃O⁺(aq)

It is possible to find pH using Henderson-Hasselbalch formula:

pH = pka + log₁₀ [A⁻] / [HA]

Where [A⁻] is concentration of conjugate base,  [CO₃²⁻] = [Na₂CO₃] and  [HA] is concentration of weak acid, [NaHCO₃] = 0.20M.

pH is desire pH and pKa (<em>10.00</em>) is -log pka = -log 4.7x10⁻¹¹ = <em>10.33</em>

<em />

Replacing these values:

10.00 = 10.33 + log₁₀ [Na₂CO₃] / [0.20]

<em> [Na₂CO₃] = 0.094M</em>

<em />

5 0
3 years ago
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