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UkoKoshka [18]
2 years ago
7

If 3.5 g of element X reacts with 10.5 g of element Y to form the compound XY.

Chemistry
1 answer:
irina [24]2 years ago
8 0

Answer:

The percentage by mass of element X is 25 %.

The percentage by mass of element Y is 75 %

Explanation:

X + Y ⇒ XY

3.5 g of element X + 10.5 g of element Y = 14g in total

⇒Element X : 3.5g / 14g = 0.25 ⇒ x 100 % = 25 %

⇒Element Y : 10.5 / 14 = 0.75 ⇒ x 100 % = 75 %

The percentage by mass of element X is 25 %.

The percentage by mass of element Y is 75 %

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Marat540 [252]
The answer is 523000000000
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2 years ago
In an experiment, the density of an unknown liquid was calculated to be 0.78 g/ml. if the accepted value is 0.75 g/ml, calculate
Vikki [24]
Percentage error is the relative error your measured value is from the true or accepted value. The formula for percentage error is written below:

Percentage error = |True Value - Measured Value|/True Value   * 100
Percentage error = |0.75 g/mL - 0.78 g/mL|/0.75 g/mL  * 100
Percentage error = 4%
6 0
2 years ago
Write a balanced equation for the transmutation that occurs when a scandium-48 nucleus undergoes beta decay.
Tju [1.3M]

Answer:

A scandium-48 nucleus undergoes beta-minus decay to produce a titanium-48 nucleus.

\rm ^{48}_{21}Sc \to ^{48}_{22}Ti + ^{\phantom{1}\,0}_{-1}e^{-} + \bar{\mathnormal{v}}_e.

Explanation:

There are two types of beta decay modes: beta-minus and beta-plus.

In both decay modes, the mass number of the nucleus stays the same.

However, in a beta-minus decay, the atomic number of the nucleus increases by one. In a beta-plus decay, the atomic number decreases by one.

Each beta-minus decay releases one electron and one electron antineutrino. Each beta-plus decay releases one positron and one electron neutrino.

Look up the atomic number and relative atomic mass for the element scandium.

  • The atomic number of \rm Sc is 21.
  • The relative atomic mass of \rm Sc is approximately 45.0.

This question did not specify whether the decay here is beta-plus or a beta-minus. However, the relative atomic mass of this element can give a rough estimate of the mode of decay.

Each element (e.g, \rm Sc) can have multiple isotopes. These isotopes differ in mass. The relative atomic mass of an element is an average  across all isotopes of this element. This mass is weighted based on the relative abundance of the isotopes. Its value should be closest to the most stable (and hence the most abundant) isotope.

The mass number of scandium-48 is significantly larger than the relative atomic mass of this element. In other words, this isotope contains more neutrons than isotopes that are more stable. There's a tendency for that neutron to convert to a proton- by beta-minus decay, for example.

The atomic number of the nucleus will increase by 1. 21 + 1 = 22. That corresponds to titanium. The mass number stays the same at 48. Hence the daughter nucleus would be titanium-48. Note that two other particles: one electron and one electron \rm e^{-} and one antineutrino \bar{v}_{\text{e}} (note the bar.) The neutrino helps balance the lepton number of this reaction.

6 0
2 years ago
What is molarity of 3 mole of hydrochloric acid in 3L of water
Mila [183]

Answer:

1

Explanation:

6 0
2 years ago
Identify the conjugate acid base pair <br> H3PO4(ag)+CO32=HCO3-(ag)+HPO42-(ag)
viktelen [127]

Answer:

H₃PO₄/H₂PO₄⁻ and HCO₃⁻/CO₃²⁻

Explanation:

An acid is a proton donor; a base is a proton acceptor.

Thus, H₃PO₄ is the acid, because it donates a proton to the carbonate ion.

CO₃²⁻ is the base, because it accepts a proton from the phosphoric acid.

The conjugate base is what's left after the acid has given up its proton.

The conjugate acid is what's formed when the base has accepted a proton.

H₃PO₄/H₂PO₄⁻ make one conjugate acid/base pair, and HCO₃⁻/CO₃²⁻ are the other conjugate acid/base pair.

H₃PO₄ + CO₃²⁻ ⇌ H₂PO₄⁻ + HCO₃⁻

acid       base         conj.       conj.

                               base       acid

3 0
2 years ago
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