A runner completes a 5-mile run.how many yards did she run

I got some chemistry for yall

ludmilkaskok [199]

Answer:

neon

chlorine

sulfur

nitrogen

silicon

boron

calcium

sodium

Explanation:

8 0

3 years ago

Gifblaar is a small South African shrub and one of the most poisonous plants known because it contains fluoroacetic acid (FCH2CO

PSYCHO15rus [73]

[H_{3}O^{+}] = 0.00770 M

The equilibrium equation representing the dissociation of $FCH_{2}COOH$

$FCH_{2}COOH(aq) + H_{2}O (l) FCH_{2}COO^{-}(aq)+ H_{3}O^{+}(aq)$

Given [H_{3}O^{+}] = 0.00770 M

Let the initial concentration of acid be x and change y

So y = $[H_{3}O^{+}]$ = $[FCH_{2}COO^{-}]$ = 0.00770 M

$pK_{a} = 2.59K_{a} = 10^{-2.59} = 0.00257 M$

$K_{a} = \frac{(0.00770 M)(0.00770 M)}{x - 0.00770}$

$0.00257 = \frac{0.00005929}{x - 0.00770}$

0.00257 x - 0.00001979 = 0.00005929

x = 0.031 M

Therefore, initial concentration of the weak acid is 0.031 M

4 0

4 years ago

PLEASE HELPPP!!!!

aksik [14]

Answer:

b. 11.90 Liters

Explanation:

The balanced equation for the mentioned reaction is:

3O₂ + 4Al → 2Al₂O₃,

It is clear that 3.0 moles of O₂ react with 4.0 moles of Al to produce 2.0 Al₂O₃.

Firstly, we need to calculate the no. of moles (n) of 36.12 g of Al₂O₃:

n = mass/molar mass = (44.18 g)/(101.96 g/mol) = 0.4333 mol.

using cross multiplication:

3.0 mol of O₂ produces → 2.0 mol of Al₂O₃.

??? mol of O₂ produces → 0.4333 mol of Al₂O₃.

∴ The no. of moles of O₂ needed to produce 36.12 grams of Al₂O₃ = (3.0 mol)(0.4333 mol)/(2.0 mol) = 0.65 mol.

Now, we can find the volume of O₂ used during the experiment:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = 1.3 atm).

V is the volume of the gas in L (V = ??? L).

n is the no. of moles of the gas in mol (n = 0.65 mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (T = 290 K).

∴ V = nRT/P = (0.65 mol)(0.0821 L.atm/mol.K)(290 K)/(1.3 atm) = 11.9 L.

So, the right choice is: b. 11.90 Liters.

8 0

4 years ago

Hydrogen gas caught fire quickly in the Hindenberg accident. In comparison, neon gas and helium gas are nonreactive. This is why

Phoenix [80]

Answer:

Helium and Neon have similar chemical properties because both of them completely fill the outer shell of their atoms' electrons, so there is nothing to share with other atoms, neither with the same element nor with any other element.

Explanation:

Helium and Neon are both noble gases . As elements react, their atoms, by losing, acquiring, or sharing electrons, complete their outer shells. Noble gas atoms already have full outer shells, so there is no tendency for them to lose, gain, or share electrons. There are incomplete outer shells of atoms of group 1 and 7 elements (so they are reactive)

Chemical properties of HELIUM and NEON -:

In group 8(or 0) of the periodic table, on the far right side, the Noble Gases are contained. Helium, neon, argon, krypton, xenon and radon are their names.

They are extremely colourless and unreactive.

They do not form bonds, so they still remain as single (monatomic) atoms.

There is very little chemical reactivity in them.

Hence, helium and neon have similar chemical properties as they are the most stable due to having the maximum number of valence electrons their outer shell can hold.

6 0

3 years ago

Is vinegar a compound or a mixture?

Nady [450]

Vinegar is a mixture because other thing are added to make a whole new thing

7 0

4 years ago