Help! 7th Grade Math!

Describe how to determine the molar mass of a compound

nirvana33 [79]

Multiply the atomic weight

3 0

2 years ago

Read 2 more answers

I really need help it's urgent help ! Don't ignore it .Your work will be appreciated and don't spam

gtnhenbr [62]

ツ here your answer

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A)Potassium bromide(aq) + Barium iodide(aq) → Potassium iodide(aq) + Barium bromide(s)

2KBr(aq)+BaI2(aq) → 2KI(aq)+BaBr2(s)

B)Balance the Chemical Equation for the reaction of calcium carbonate with hydrochloric acid:
CaCO3+ HCl -> CaCl2 + CO2 + H2O To balance chemical equations we need to look at each element individually on both sides of the equation. calcium carbonate is a chemical compound with the formula CaCO3.

Mark me in brainlist

8 0

3 years ago

"Calculate the number of millimoles in 500 mg of each of the following amino acids: alanine (MW = 89), leucine (131), tryptophan

Cloud [144]

Answer:

- Alanine = 5.61 mmoles

- Leucine = 3.81 mmoles

- Tryptophan = 2.45 mmoles

- Cysteine = 4.13 mmoles

- Glutamic acid = 3.40 mmoles

Explanation:

Mass / Molar mass = Moles

Milimoles = Mol . 1000

500 mg / 1000 = 0.5 g

- Alanine = 0.5 g / 89 g/m → 5.61x10⁻³ moles . 1000 = 5.61mmoles

- Leucine = 0.5 g / 131 g/m → 3.81 x10⁻³ moles . 1000 = 3.81 mmoles

- Tryptophan = 0.5 g / 204 g/m → 2.45x10⁻³ moles . 1000 = 2.45 mmoles

- Cysteine = 0.5 g / 121 g/m → 4.13x10⁻³ moles . 1000 = 4.13 mmoles

- Glutamic acid = 0.5 g 147 g/m → 3.40x10⁻³ moles . 1000 = 3.4 mmoles

5 0

3 years ago

How many hours will it take for the concentration of methyl isonitrile to drop to 15.0 % of its initial value?

SpyIntel [72]

Answer:

The concentration of methyl isonitrile will become 15% of the initial value after 10.31 hrs.

Explanation:

As the data the rate constant is not given in this description, However from observing the complete question the rate constant is given as a rate constant of 5.11x10-5s-1 at 472k .

Now the ratio of two concentrations is given as

$ln (\frac{C}{C_0})=-kt$

Here C/C_0 is the ratio of concentration which is given as 15% or 0.15.

k is the rate constant which is given as $5.11 \times 10^{-5} \, s^{-1}$

So time t is given as

$ln (\frac{C}{C_0})=-kt\\ln(0.15)=-5.11 \times 10^{-5} \times t\\t=\frac{ln(0.15)}{-5.11 \times 10^{-5} }\\t=37125.6 s\\t=37125.6/3600 \\t= 10.31 \, hrs$

So the concentration will become 15% of the initial value after 10.31 hrs.

7 0

3 years ago

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Precipitation _____. occurs equally all over the globe is the change in state from a gas to a liquid happens when ice changes in

LenKa [72]

<h3>Answer;</h3>

exceeds evaporation over land

Precipitation exceeds evaporation over land

<h3>Explanation;</h3>

In order to maintain earths water balance, evaporation exceeds precipitation over oceans but precipitation exceeds evaporation over land.
Water evaporates into the atmosphere from the ocean and to a much lesser extent from the continents. Winds transport this moisture-laden air, often great distances, until conditions cause the moisture to condense into clouds and to precipitate and fall.
Most precipitation originates by evaporation from the oceans. Over time, water evaporated from the oceans is replenished by inflow of freshwater from rivers and streams.

4 0

3 years ago