True or false only ocean waves have troughs and crest

What is the empirical formula of a compound that is 41.4% Strontium, 13.24%

Pepsi [2]

Answer:

Empirical Formula N2O6Sr Strontium Nitrate

Explanation:

N=13.2% O=45.4% Sr=41.4%

6 0

3 years ago

Be sure to answer all parts. calculate δg ocell for the reaction between cr(s) and cu2+(aq). e ocell = 1.08 j/c. enter your answ

Mademuasel [1]

Answer:

$\boxed{-6.29 \times10^{5}\text{ J}}$

Explanation:

Step 1. Determine the cell potential

E°/V

2×[Cr ⟶ Cr³⁺ + 3e⁻] 0.744 V

3×[Cu²⁺ + 2e⁻ ⟶ Cu] 0.3419 V

2Cr + 3Cu²⁺ ⟶ 3Cu + 2Cr³⁺ 1.086 V

Step 2. Calculate ΔG°

$\Delta G^{\circ} = -nFE_{\text{cell}}^{^{\circ}} = -6 \times 96 485 \times 1.086 = \text{-629 000 J}\\\\= \boxed{-6.29 \times10^{5}\text{ J}}$

6 0

3 years ago

Calculate the number of O atoms in 0.364 g of CaSO4 · 2H2O

Nikolay [14]

Answer:

= 7.66 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

Explanation:

For problems like this posting, one needs an understanding of the following topics:

The definition of the mole

1 mole of substance = mass in grams of substance containing 1 Avogadro's Number ( = 6.023 x 10²³ ) of particles of the specified substance. This is generally one formula weight of the substance of interest. From this, the following equivalent relationships should be memorized:

1 mole = 1 formula weight = 1 mole weight (g)= 6.023 x 10²³ particles

Converting grams to moles:

Given grams => moles = grams/gram formula wt

Converting moles to grams:

Given moles => grams = moles x gram formula wt

_________________________________________________________

Calculate the number of O atoms in 0.364 g of CaSO₄ · 2H₂O.

Given mass CaSO₄ · 2H₂O = 0.364 grams

Formula Wt CaSO₄ · 2H₂O = 172 g/mole

moles CaSO₄ · 2H₂O = mass CaSO4 · 2H2O / formula Wt. CaSO₄ · 2H₂O

= 0.364 g CaSO₄·2H₂O / 172 g CaSO4·2H2O

= (0.364/172) mole CaSO₄·2H₂O

= 2.12 x 10⁻³ mole CaSO₄·2H₂O

∴ number of Oxy (O) atoms in 0.364 grams CaSO₄·2H₂O

= (2.12 x 10⁻³ mole CaSO₄ · 2H₂O)(6.023 x 10²³ molecules CaSO₄· 2H₂O/ mole)

= 1.276876 x 10²¹molecules CaSO₄· 2H₂O CaSO₄2H₂O

= 1.276876 x 10²¹ molecules CaSO₄· 2H₂O x 6 oxygen atoms / molecule

= 7.661256 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

= 7.66 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

8 0

3 years ago

Carbon-14 has a half-life of 5,730 years. It is used in "carbon dating" to determine the age of once living organisms. How much

Nookie1986 [14]

Answer:

18 grams

Explanation:

Because 17,190 yrs divided by the amount of years it takes for a half-life to occur is 3. So 3 half life’s happen, so you divide 144/2 once, equaling 72. You divide 72/2 again (another half-life) and you get 36. You then calculate the third half life by dividing 36/2 which equals 18 grams.

7 0

3 years ago

How can you demonstrate that a piece of chalk has mass?

Dmitry [639]

You can demonstrate that a piece of chalk has mass by putting it on a pan scale. Pan scales determine mass in grams. Also if the mass feels like it has some weight to it (although not to be confused with weight, they are two different things!), it most likely has mass.
Hope this helps!!

8 0

3 years ago